Electronic device, method and storage medium for wireless communication system

ABSTRACT

The disclosure relates to an electronic device and method for a wireless communication system, and a storage medium. Various embodiments regarding beam management are described. In one embodiment, an electronic device for a terminal device side in a wireless communication system can comprise a processing circuit system. The processing circuit system can be configured to obtain random access configuration information, and send a random access preamble based on the random access configuration information, so as to indicate one or more transmission beams of a base station side, in a downlink, paired with one or more receiving beams at the terminal device side.

CROSS-REFERENCE TO RELATED APPLICATIONS

This present application is a continuation of U.S. application Ser. No.17/980,564, filed Nov. 4, 2022, which is a continuation of U.S.application Ser. No. 16/612,408, filed Nov. 11, 2019 (now U.S. Pat. No.11,515,915), which is based on PCT filing PCT/CN2018/091487, filed Jun.15, 2018, which claims priority to CN 201710469943.2, filed Jun. 20,2017, the entire contents of each are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to wireless communicationsystem, and in particular, to beam management techniques related tobeamforming.

BACKGROUND ART

In recent years, with the development and wide application of mobileinternet technology, wireless communication has unprecedentedly metpeople's needs for voice and data communication. In order to provideeven higher communication quality and capacity, wireless communicationsystem employs various technologies at different layers, such asbeamforming techniques. Beamforming can provide beamforming gain tocompensate for loss of radio signals by increasing the directivity ofantenna transmission and/or reception. In future wireless communicationsystems (such as 5G systems like NR (New Radio) system, for example),the number of antenna ports at the base station and the terminal devicesides will further increase. For example, the number of antenna ports atthe base station side may increase to hundreds or even more,constituting a Massive MIMO system. Thus, in large-scale antennasystems, beamforming will have a larger application space.

Currently, beamforming is more used for the data transceiving processbetween a base station and a terminal device. However, the initialconnection/synchronization between the terminal device and the basestation (including, for example, the base station transmitting aSynchronization Signal (SS), and the terminal device transmitting therandom access signal to the base station) is the first step to enablethe terminal device to communicate properly with the base station.Therefore, beamforming technology can be considered for the initialconnection/synchronization between the terminal device and the basestation. For example, beamforming technology can be considered for thetransceiving process of the synchronization signal as well as thetransceiving process of the random access signal.

SUMMARY OF THE INVENTION

Aspects of the present disclosure relate to beam management inbeamforming techniques of wireless communication system.

One aspect of the present disclosure relates to an electronic device fora base station side in a wireless communication system. According to oneembodiment, the electronic device may comprise processing circuitry. Theprocessing circuitry can be configured to repetitively transmit asynchronization signal to a terminal device by using different transmitbeams based on a transmit beam configuration, the synchronization signalindicating information of a transmit beam used to transmit thesynchronization signal. The processing circuitry can further beconfigured to obtain feedback from the terminal device, the feedbackcomprising information of the transmit beam for being used in transmitbeam management.

Another aspect of the present disclosure relates to an electronic devicefor a terminal device side in a wireless communication system. Accordingto one embodiment, the electronic device comprises a processingcircuitry. The processing circuitry can be configured to receive asynchronization signal based on a transmit beam configuration of a basestation side of the wireless communication system, the synchronizationsignal being able to indicate information of a transmit beam used totransmit the synchronization signal by the base station. The processingcircuitry can further be configured to provide feedback to the basestation, and the feedback can comprise information of the transmit beamfor being used by the base station in transmit beam management.

Another aspect of the disclosure relates to a method of radiocommunication. In one embodiment, the method may comprise repetitivelytransmitting a synchronization signal to a terminal device by using adifferent transmit beam based on the transmit beam configuration, thesynchronization signal being able to indicate information of a transmitbeam used to transmit the synchronization signal; and obtaining feedbackfrom the terminal device, the feedback comprising information of thetransmit beam for being used in transmit beam management.

Another aspect of the disclosure relates to another method of radiocommunication. In one embodiment, the method may comprise receiving asynchronization signal based on a transmit beam configuration of a basestation side in a wireless communication system, the synchronizationsignal being able to indicate information of a transmit beam used totransmit the synchronization signal by the base station; and providingfeedback to the base station, the feedback comprising information of thetransmit beam for being used by the base station in transmit beammanagement.

Another aspect of the present disclosure relates to an electronic devicefor a base station side in a wireless communication system. According toone embodiment, the electronic device may comprise processing circuitry.The processing circuitry can be configured to receive a transmit beamconfiguration from another base station that transmits a synchronizationsignal to a terminal device based on the transmit beam configuration.The processing circuitry can further be configured to transmit atransmit beam configuration to the terminal device.

Another aspect of the present disclosure relates to an electronic devicefor a terminal device side in a wireless communication system. Accordingto one embodiment, the electronic device comprises a processingcircuitry. The processing circuitry may be configured to obtain randomaccess configuration information; and transmit a random access preamblebased on the random access configuration information to indicate one ormore transmit beams at a base station side paired with one or morereceive beams at the terminal device side in the downlink.

Another aspect of the present disclosure relates to an electronic devicefor a base station side in a wireless communication system. According toone embodiment, the electronic device can comprise processing circuitry.The processing circuitry can be configured to transmit random accessconfiguration information; and receive a random access preambletransmitted from a terminal device, to obtain one or more transmit beamsat the base station side paired with one or more receive beams at theterminal device side in the downlink.

Another aspect of the disclosure relates to a method of radiocommunication. In one embodiment, the method can comprise obtainingrandom access configuration information; and transmitting a randomaccess preamble based on the random access configuration information, toindicate one or more transmit beams at a base station side paired withone or more receive beams at a terminal device side in the downlink.

Another aspect of the disclosure relates to another method of radiocommunication. In one embodiment, the method may comprise transmittingrandom access configuration information; and receiving a random accesspreamble transmitted from a terminal device, to obtain one or moretransmit beams at a base station side paired with one or more receivebeams at the terminal device side in the downlink.

Another aspect of the disclosure relates to a computer-readable storagemedium storing one or more instructions. In some embodiments, the one ormore instructions can, when executed by one or more processors of anelectronic device, cause the electronic device to perform methods inaccordance with various embodiments herein.

Another aspect of the disclosure relates to various apparatus, includingmeans or units for performing the operations of the methods inaccordance with embodiments herein.

The above summary is provided to summarize some exemplary embodiments inorder to provide a basic understanding of the various aspects of thesubject matter described herein. Therefore, the above-described featuresare merely examples and should not be construed as limiting the scope orspirit of the subject matter described herein in any way. Otherfeatures, aspects, and advantages of the subject matter described hereinwill become apparent from the Detailed Description described below inconjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present disclosure can be achieved byreferring to the detailed description given hereinafter in connectionwith the accompanying drawings, wherein same or similar reference signsare used to indicate same or similar components throughout the figures.The figures are included in the specification and form a part of thespecification along with the following detailed descriptions, forfurther illustrating embodiments herein and explaining the theory andadvantages of the present disclosure. Wherein:

FIG. 1 depicts an exemplary cell synchronization and random accessprocess in a wireless communication system.

FIGS. 2A-2D depict an exemplary beam scanning process in beamformingtechniques.

FIG. 3A illustrates an exemplary electronic device for a base stationside in accordance with an embodiment herein.

FIG. 3B illustrates an exemplary electronic device for a terminal deviceside in accordance with an embodiment herein.

FIGS. 4A-4D illustrate exemplary time domain frequency domain resourcesfor a synchronization signal in accordance with an embodiment herein.

FIGS. 5A and 5B illustrate an exemplary synchronization signal timewindow in accordance with an embodiment herein.

FIGS. 6A-6C illustrate an exemplary transmit beam configuration of abase station side in accordance with an embodiment herein.

FIGS. 7A-7D illustrate an exemplary correspondence between a transmitbeam and a synchronization signal time window in accordance with anembodiment herein.

FIGS. 8A and 8B illustrate an exemplary receive beam arrangement at theterminal device side under a base station side specific transmit beamconfiguration, in accordance with an embodiment herein.

FIG. 9 illustrates an exemplary operation of a secondary node additionin accordance with an embodiment herein.

FIG. 10 illustrates example performance of beam detection in accordancewith an embodiment herein.

FIGS. 11A and 11B illustrate an example manner of indicating informationof a transmit beam at base station side, in accordance with anembodiment herein.

FIGS. 12A and 12B illustrate an example method for communication inaccordance with an embodiment herein.

FIG. 13 illustrates an exemplary electronic device for a base stationside in accordance with an embodiment herein,

FIG. 14 illustrates an example hierarchical transmit beam scanningprocess flow in accordance with an embodiment herein.

FIG. 15A illustrates an exemplary electronic device for a terminaldevice side according to an embodiment herein,

FIG. 15B illustrates an exemplary electronic device for a base stationside in accordance with an embodiment herein.

FIG. 16 illustrates an exemplary random access time window in accordancewith an embodiment herein.

FIGS. 17A and 17B illustrate an exemplary receive beam configuration atthe base station side in accordance with an embodiment herein.

FIG. 18 illustrates an exemplary correspondence between receive beam atthe base station side and a random access time window in accordance withan embodiment herein.

FIGS. 19A and 19B illustrate an exemplary transmit beam arrangement on aterminal device side under a base station side specific receive beamconfiguration, in accordance with an embodiment herein.

FIGS. 20A and 20B illustrate an example method of transmitting a randomaccess preamble in accordance with an embodiment herein.

FIG. 21A illustrates an exemplary method in which a terminal devicetransmits a random access preamble according to an embodiment herein.

FIG. 21B illustrates an exemplary method in which a base stationreceives a random access preamble in accordance with an embodimentherein.

FIG. 22 illustrates an exemplary method of retransmitting a randomaccess preamble in accordance with an embodiment herein.

FIGS. 23A and 23B illustrate an example method for communication inaccordance with an embodiment herein.

FIG. 24 is a block diagram of example structure of a personal computerwhich is an information processing device that can be employed in anembodiment herein;

FIG. 25 is a block diagram illustrating a first example of a schematicconfiguration of a gNB to which the technology of the present disclosurecan be applied;

FIG. 26 is a block diagram illustrating a second example of a schematicconfiguration of a gNB to which the technology of the present disclosurecan be applied;

FIG. 27 is a block diagram illustrating an example of a schematicconfiguration of a smartphone to which the technology of the presentdisclosure can be applied; and

FIG. 28 is a block diagram illustrating an example of a schematicconfiguration of a automobile navigation device to which the technologyof the present disclosure can be applied.

While the embodiments herein are susceptible to various modificationsand alternative forms, the specific embodiments thereof are illustratedin the drawings by way of example and are described in detail herein. Itshould be understood, however, that the drawings and the detaileddescription thereof are not intended to limit the embodiments to thespecific forms as disclosed, rather, it is intended to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the claims.

DESCRIPTION OF EMBODIMENTS

Exemplary embodiments herein will be described hereinafter withreference to the accompanying drawings. For the sake of clarity andconciseness, not all features of a actual implementation are describedin the specification. However, it should be appreciated thatimplementation specific decisions must be made in the development of anysuch actual embodiment, so as to achieve specific goals of thedeveloper. For example, to comply with constrain conditions related tosystem and business, and these constrain conditions may vary fromimplementation to implementation. Furthermore, it will also beappreciated that the development work may be more complicated and timeconsuming, although such development work is merely a routine task forthose skilled in the art having benefit of this disclosure.

Only the device structure and/or operational steps closely related tothe solutions according to the present disclosure are shown in thedrawings in order to avoid obscuring the present disclosure withunnecessary detail, and other details that has little relation to thepresent disclosure are omitted.

Initial Connection/Synchronization Process Between Base Stations andTerminal Devices

An exemplary initial connection/synchronization process between basestation and terminal device in a wireless communication system,including cell synchronization and random access (RA) process, is firstdescribed in conjunction with FIG. 1 . In general, a wirelesscommunication system may include a plurality of base stations, each ofwhich may serve several terminal devices within a respective coveragearea (e.g., a cell). An exemplary cell synchronization and RA processbetween the terminal device 110 and the base station 120 is shown inFIG. 1 , and the terminal device 110 is one of the several terminaldevices served by the base station 120. This process may also beapplicable to any terminal device in a wireless communication system.

The terminal device 110 first needs to perform cell search when bootingor to be handed-over to the base station 120. One of the purposes of thecell search is to enable the terminal device 110 to obtain the cellframe timing of the base station 120, to derive the starting position ofthe downlink frame. On the other hand, the base station 120 transmitsthe synchronization signal 101 so as to enable the terminal device 110to obtain the cell frame timing, and the base station 120 canperiodically perform synchronization signal transmission, for example.In general, a synchronization sequence may be included in thesynchronization signal, the synchronization sequence set from which thesynchronization sequence is selected is known to both the base stationand the terminal device. In an LTE system, for example, asynchronization signal comprises a Primary Synchronization Signal (PSS)and a Secondary Synchronization Signal (SSS). In one example, the PSSmay be a Zadoff-Chu sequence of length 63, and the SSS may be a sequenceof length 62 and derived from two cascade M-sequences of length 31.Moreover, the synchronization signal may be transmitted with a certaintime period or time pattern, for example, the synchronization signal maybe transmitted at fixed locations (e.g., fixed subframes, time slots,and symbol locations) in the downlink frame. In this way, the terminaldevice 110 may perform a correlation operation on the received signal ina single subframe and the synchronization sequences in the knownsynchronization sequence set one by one at the carrier center, and thepeak position of the correlation then corresponds to the position of thesynchronization signal in the downlink frame, whereby the terminaldevice 110 may obtain downlink cell synchronization.

After obtaining downlink cell synchronization, the terminal device 110may receive system information of the cell at an appropriate position inthe downlink frame. The system information can be periodicallybroadcasted by the base station 120 through a channel for broadcasting(e.g., broadcast channel PBCH, shared channel PDSCH, etc.), and caninclude information necessary for the terminal device 110 to access thebase station 120, such as RA related information.

Thereafter, in order to obtain uplink cell synchronization, the terminaldevice 110 needs to perform a RA process. An exemplary RA processoperates as follows. At 102, the terminal device 110 may notify the basestation 120 of its access behavior by transmitting a RA preamble (e.g.,included in the MSG-1) to the base station 120. The transmission of theRA preamble enables the base station 120 to estimate the uplink timingadvance (TA) of the terminal device. At 103, the base station 120 maynotify the terminal device 110 of the above timing advance bytransmitting a RA response (e.g., included in the MSG-2) to the terminaldevice 110. The terminal device 110 may implement uplink cellsynchronization by this timing advance. The RA response can also includeinformation of the uplink resource, and the terminal device 110 may usethe uplink resource in the following operation 104. For acontention-based RA process, at 104, the terminal device 110 maytransmit the terminal device identification and possibly otherinformation (e.g., included in the MSG-3) through the above scheduleduplink resources. The base station 120 can determine the contentionresolution result by the terminal device identification. At 105, basestation 120 can inform terminal device 110 of the contention resolutionresult (e.g., included in MSG-4). At this time, if the contentionsucceeds, the terminal device 110 successfully accesses the base station120, and the RA process ends; otherwise, the terminal device 110 needsto repeat operations 102 to 105 of the RA process. In one example, afterthe RA process succeeds, the initial connection/synchronization processbetween the terminal device and the base station can be considered to becomplete, and the terminal device may perform subsequent communicationwith the base station.

Overview of Beamforming and Beam Scanning

Beamforming generally refers to in consideration of the strongdirectivity of the antenna transmission and/or reception, so that eachtransmit beam and/or receive beam is limited to pointing a specificdirection and beam coverage, and the coverage of each beam is narrowerthan the full-width beam, but the gain of the beam increases. Thesetransmit beams and/or receive beams may be approximately combined into afull-width beam. A full-width beam may refer to a beam withoutbeamforming, i.e. its beamwidth is not narrowed by beamformingprocessing. For example, the beam of an omnidirectional antenna can beconsidered to be a full-width beam. In some instances of physicalimplementation, the communication device at the transmitting end has aplurality of radio frequency links, each of which is connected to aplurality of antennas and their phase shifters, and the signals on eachradio frequency link are superimposedly transmitted into the air by theplurality of antennas with different phases to form a transmit beam. Thecontrol unit of the communication device at transmitting end determinesthe phase values of the corresponding plurality of antennas according tothe target transmit beam direction, and configures respective phaseshifters, thereby controlling the transmit beamforming. Accordingly, thecommunication device at receiving end has one or more radio frequencylinks, each of which is connected to a plurality of antennas and theirphase shifters, and the radio signals in the air are superimposedlyreceived by the plurality of antennas having different phases into theRF link to form a receive beam. The control unit of the communicationdevice at receiving end determines the phase values of the correspondingplurality of antennas according to the target receive beam direction,and configures respective phase shifters, thereby controlling thereceive beamforming. In some examples, control units of communicationdevices configure phase shifters of a plurality of antennas of eachradio frequency link according to a predetermined codebook. The codebookcomprises a plurality of codewords, each codeword corresponding to onebeam direction, indicating a phase combination of phase shifters.

In beamforming, due to the strong directivity of antenna transmissionand/or reception, paired transmit and receive beams are needed in thedownlink or uplink to ensure beamforming gain is achieved. Therefore,such paired transmit and receive beams in the downlink or uplink can becollected and maintained, that is, beam management is performed. Beammanagement involves two important aspects, namely beam scanning andscanning result interaction. The beam scanning can include a transmitbeam scan and a receive beam scan, which refer to transmit and receive,respectively, different beams in a predetermined manner over a period oftime to cover a certain spatial region, thereby finding transmit andreceive beams suitable for a certain azimuth spatial region. Takingdownlink as an example, since one terminal device is usually located ata specific orientation of the base station, there is usually only one(or more) specific transmit beams at the base station side suitable forcommunicating with the terminal device. There is also usually one (ormore) receive beams that mate with the specific transmit beam at theterminal side. The terminal device may report the specific transmit beamof the base station side mating with it to the base station by using thescan result report. In the transceiving of synchronization signals, apair of matching transmit and receive beams may refer to transmit andreceive beam pairs that cause correlation results of synchronizationsequence correlation operations when the synchronization signal isreceived to conform to a certain threshold level. It will be understoodthat in subsequent transceiving of data, the communication quality(e.g., received signal strength (such as RSRP), signal to interferenceand noise ratio (such as CQI), bit error rate (such as BER, BLER), etc.)via the pair of transmit and receive beams may also conform to certaincommunication quality demands.

Beam scanning in beamforming techniques is described below inconjunction with FIGS. 2A-2D. In beamforming, the transmitting end canperform transmit beam scanning through a plurality of transmit beams. Inthe example of FIG. 2A, the transmitting end is provided with fourtransmit beams, and in the example of FIG. 2B, the transmitting end isprovided with three transmit beams. The receiving end may or may not usereceive beamforming depending on the configuration or applicationrequirements. In the example of FIG. 2A, the receiving end uses receivebeamforming and performs receive beam scanning through three receivebeams. In the example of FIG. 2B, the receiving end does not use receivebeamforming and is only provided with one full-width receive beam. Inbeamforming, the transmitting end and/or the receiving end may also beprovided with hierarchical transmit beams, such as first level transmitbeams (also called coarse transmit beams) and second level transmitbeams (also called fine transmit beams). In the example of FIG. 2C, thetransmitting end is provided with three first level transmit beams(i.e., TX_B1 to TX_B3), and each first level transmit beam is furtherprovided with two second level transmit beams (e.g., two fine transmitbeams of TX_B1 are TX_B1, 1 and TX_B1, 2, and the rest are similar.) Inthe example of FIG. 2D, both the transmitting end and the receiving endare provided with hierarchical transmit beam. In FIG. 2D, the transmitbeams of the transmitting end are similar to those of FIG. 2C, and thereceiving end is provided with three first level receive beams (i.e.,RX_B1 to RX_B3), and each first level receive beam is further providedwith two second level receive beams (for example, the two fine transmitbeams of RX_B1 are RX_B1, 1 and RX_B1, 2, and the rest are similar). Asshown in FIG. 2C and FIG. 2D, the beamwidth of the coarse transmit beamcan be wider than that of the fine transmit beam, and the gain of thefine transmit beam can be larger than that of the coarse transmit beam.

In the beam scanning process, the transmitting end may perform transmitbeam transmission one by one (i.e., transmit beam scanning). Forexample, considering situations of the receiving end, each transmit beamcan be transmitted once or repetitively transmitted multiple times. Thetransmission of each transmit beam may be received at the receiving endone by one by using receive beams (i.e., receive beam scanning) todetermine matching transmit and receive beams pairs. For example, in theexample of FIG. 2A, the transmitting end can first repetitively transmitthree times using the transmit beam TX_B1. Accordingly, the receivingend can receive the corresponding one transmission using the receivebeams RX_B1 to RX_B3 one by one, and derive the respective correlationof synchronization sequences. Next, the transmitting end canrepetitively transmit three times using the transmit beam TX_B2, and thereceiving end can receive the corresponding one transmission using thereceive beams RX_B1 to RX_B3 one by one and derive the respectivecorrelation of synchronization sequences. After the transmitting endrepetitively transmits using the transmit beams TX_B3 and TX_B4, thereceiving end can determine the matching transmit and receive beams pairbased on the derived correlation of synchronization sequences. Thus,subsequent communication between the transmitting end and the receivingend can be performed using this transmit and receive beams pair. Thenumber of repetitive transmissions of each transmit beam in the aboveexample can be an integer multiple of the number of receive beams. Inthe case that the receiving end has multiple radio frequency links sothat multiple receive beams can be used for receiving simultaneously,the transmitting end does not have to repetitively transmit eachtransmit beam, but only sequentially transmit TX_B1˜TX_B4. FIG. 2B is anexample in which the receiving end does not use receive beamforming. InFIG. 2B, for each transmission at the transmitting end, the terminaldevice receives using a full-width receive beam and determinesrespective synchronization sequence correlation to determine a transmitbeam that matches the full-width receive beam. Thus, in subsequentcommunications between the transmitting end and the receiving end, thetransmitting end will communicate using the determined transmit beam.

In the case of hierarchical transmit beams in FIG. 2C, a matching firstlevel transmit beam can be determined first, followed by determining amatching second level transmit beam under the matching first leveltransmit beam. For example, the transmitting end can first perform afirst level transmit beam scanning, and the receiving end may determinea first level transmit beam matching thereto in a similar manner asdescribed above. When the transmitting end performs beam scanningthrough the second level transmit beams under the matching first leveltransmit beam, the receiving end can similarly determine the secondlevel transmit beam matching thereto. The second level transmit beam andthe matching receive beam are thus ultimately determined as matchingtransmit and receive beams pair for use in subsequent communication.According to an exemplary implementation, when beam scanning isperformed through the second level transmit beams, the receiving end candirectly use the matching receive beam determined when beam scanning isperformed through the first level transmit beams as the receive beam forreceiving and determining, instead of all receive beams, thus reducingbeam scanning overhead.

In the case where the transmit beams and the receive beams are bothhierarchical in FIG. 2D, in the beam scanning, the transmitting end canfirst perform the first level transmit beam scanning, and the receivingend can receive using the corresponding first level receive beams,thereby determining the matching first level transmit beam and the firstlevel receive beam in a similar manner as described above. When thetransmitting end performs beam scanning through the second leveltransmit beams under the matching first level transmit beam, thereception can be made at the receiving end by using the second levelreceive beams under the corresponding matching first level receive beam,thus the matching second level transmit beam and second level receivebeam are determined in a similar manner as described above as matchingtransmit and receive beams pair for use in subsequent communication.

It should be understood that in downlink communication, the transmittingend can correspond to the base station 120 and the receiving end cancorrespond to the terminal device 110. In uplink communication, thetransmitting end may correspond to the terminal device 110, and thereceiving end may correspond to the base station 120. In an embodimentherein, in the case where the matching transmit and receive beams in theuplink correspond to (e.g., are the same as) the matching receive andtransmit beams in the downlink, the transmit and receive beams pair inthe uplink and downlink are referred to has symmetry. The symmetry meansthat, in terms of matching with the terminal device 110, the transmitbeam of the base station corresponds to the receive beam of the basestation 120, and the matching corresponding receive beam (or transmitbeam) can be determined according to the matching transmit beam (orreceive beam) of the base station side. In terms of matching with thebase station 120, the situation at the side of the terminal device 110is similar.

Application of Beamforming Techniques in Synchronization SignalsTransceiving

The application of the beamforming techniques in transceiving of theaforementioned synchronization signals will be briefly described below.In the field of wireless communications, beamforming techniques havebeen used to transmit data signals. According to an embodiment herein,beamforming can be used to transmit synchronization signals. Forexample, base station 120 can transmit synchronization signals usingtransmit beamforming to compensate for the loss of the synchronizationsignal to ensure that terminal device 110 properly performs downlinksynchronization and RA process. The technical solution according to thepresent disclosure can be used in various communication frequency bands,including conventional radio frequency communication bands ranging fromseveral hundred MHz to several GHz. As frequency bands in wirelesscommunication systems increase, for example using bands of 26 GHz, 60GHz or higher, radio channels will experience greater negative effectssuch as path losses, atmospheric absorption losses, etc. than lowfrequency bands (e.g., 2 GHz). Therefore, the technical solutionaccording to the present disclosure is equally applicable to, and evenmore important for, high frequency band (for example, millimeter wave)communication.

In some embodiments herein, the transmission of the synchronizationsignal can indicate information of the transmit beam used to transmitthe synchronization signal, such that the terminal device can obtain theinformation of the transmit beam by receiving the synchronizationsignal, such that beam scanning during subsequent data transmission issimplified and speeded up. According to some embodiments herein, thesynchronization signal can be repetitively transmitted to a plurality ofterminal devices including the terminal device by the base station usingdifferent transmit beams based on the transmit beam configuration, andthe synchronization signal can comprise information of the transmit beamused to transmit the synchronization signal, as described herein below.For example, in some embodiments using beamforming techniques totransmit synchronization signals, considering that base station 120 willrepetitively transmit synchronization signals in a plurality ofdifferent transmit beams, the synchronization signal time windows in thedownlink frame are redesigned, as will be described in detail hereinlater. The repetition pattern of multiple transmit beams in the transmitbeam scanning can be represented by a transmit beam configuration, and asynchronization signal can be transmitted based on the transmit beamconfiguration.

The terminal device can receive the synchronization signal in a varietyof ways. Upon receiving the synchronization signal, the terminal devicecan determine at least the transmit beam of the base station thatmatches with the terminal device and feed back the matching transmitbeam to the base station by any suitable ways, including ways describedbelow in present disclosure and any other ways. At least the matchingtransmit beam of the base station can be used for subsequentcommunication between the base station and the terminal device(including a RA process and a data transceiving process).

In one embodiment, the terminal device 110 can not use receivebeamforming when receiving the synchronization signal, thus reaching acompromise between fast synchronization and reduced subsequent beamscanning overhead. At this time, it can be considered that the terminaldevice 110 receives the synchronization signal transmitted by each ofthe transmit beams at the base station side with its own full-widthbeam, and feeds back the transmit beam of the base station side thatmatches with the full-width beam to the base station 120 when thesynchronization signal is successfully received. In another embodiment,the terminal device 110 can alternatively use receive beamforming whenreceiving the synchronization signal, thus resisting fading of the highfrequency synchronization signal and saving subsequent beam scanningoverhead. At this time, the receive beam at the terminal device side andthe transmit beam at the base station side that are matched when thesynchronization signal is successfully received can be determined, andthe matching transmit beam can be fed back to the base station 120. Thematching transmit and receive beams pair will be used directly orindirectly for subsequent communications between the base station 120and the terminal device 110 (including RA processes and datatransceiving processes). For example, the base station 120 and theterminal device 110 use the same beams for data transceiving as thematching transmit beam and the receive beam for the synchronizationsignal, in other words, the beamforming codebooks of the synchronizationsignal and the data signal are the same. For another example, the basestation 120 and the terminal device 110 use the matching transmit beamand the receive beam for the synchronization signal as the first levelbeam pair, and perform a second level beam scan within the coveragerange of the first level beam pair to determine finer receive andtransmit beam pair for used in data transceiving, in other words, thebeamforming codebooks of the synchronization signal and the data signalare different, and the beamforming codebook of the data signal is asubset of the beamforming codebook of the synchronization signal.

In some embodiments, where the terminal device also employs beamformingtechniques to receive the synchronization signal, the terminal devicemay also set the receive beam of the terminal device to receive thesynchronization signal based on the transmit beam configuration used totransmit the synchronization signal by the base station (e.g., how manytransmit beams in total, number of repetitions per transmit beam). Forexample, since the terminal device 110 needs to perform receive beamscanning, that is, using different receive beams to receive signalstransmitted by the base station side through the same transmit beam, theterminal device 110 may need to know the transmit beam configuration ofthe base station 120. In one example, the transmit beam configuration ofbase station 120 can be informed to the terminal device in advance. Forexample, the terminal device can simultaneously obtain the services ofthe base station 120 and another base station (for example, an LTE eNB)that does not perform beamforming transceiving by way of dualconnectivity, and the terminal device 110 can obtain information thetransmit beam configuration of the base station 120 from the anotherbase station. Specifically, the terminal device 110 first accesses theanother base station (which may be referred to as a primary basestation) according to a conventional manner, and the primary basestation requests the base station 120 to add it as a secondary basestation to the terminal device 110 via, for example, an Xn interface,and the base station 120 feeds back a confirmation of the secondary basestation addition request to the primary base station, which includesinformation of transmit beam configuration for synchronization signal ofbase station 120, and may also include RA configuration information insome examples. Next, the primary base station provides such information,for example, included in a radio resource control connectionreconfiguration message, to the terminal device 110 for completion ofsynchronization with the base station 120. In another example, theterminal device 110 can obtain the transmit beam configuration of thebase station 120 from the synchronization signal transmitted by the basestation 120. For example, the terminal device 110 can estimate thetransmit beam configuration of the base station 120 by the measurementprocess of the synchronization signal.

Report of Beam Scanning Results

The feedback of the matching transmit beam at the base station side bythe terminal device will be briefly described below. In an embodimentherein, in order for the terminal device 110 to be able to feed back thematching transmit beam at the base station side to the base station 120,it is necessary to indicate the transmit beam in some manner. Thematching transmit beam at the base station side can be indicated in animplicit or explicit manner, thereby reporting beam scanning results.This report of beam scanning results can be included in the RA processperformed by the terminal device. According to some embodiments, ofcourse, the feedback related to the transmit beam at the base stationside can be transmitted separately from the RA preamble, for example,before or after the RA preamble.

According to some embodiments herein, transmitting the RA preamble bythe terminal device can indicate a transmit beam at the base stationside in the downlink that matches with the reception behavior at theterminal device side, as described herein below. For example, in a casewhere the terminal device uses receive beamforming, transmitting a RApreamble by the terminal device can indicate a transmit beam at the basestation side in the downlink that matches with the receive beam at theterminal device side; and in a case where the terminal device does notuse receive beamforming, transmitting a RA preamble by the terminaldevice can indicate a transmit beam at the base station side in thedownlink that matches with the reception behavior at the terminal deviceside that does not use beamforming.

In some embodiments, the terminal device 110 transmits a RA preamblebased on the RA configuration information, to indicate a transmit beamat the base station side in the downlink that matches with the receivebeam at the terminal device side. In some embodiments, the RAconfiguration information can include a correspondence between a receivebeam at the base station side and a plurality of RA time windows. In oneembodiment, the correspondence may include a correspondence betweenmultiple levels of receive beams at the base station side and multipleRA time windows. The terminal device 110 can transmit a RA preamblebased on this correspondence. In one example, the base station canidentify the corresponding transmit beam at the base station side byreceiving the RA preamble in a particular time window. This is oneexample of indicating a matching transmit beam at the base station sidein an implicit manner.

In some embodiments, a transmit beam at the base station side thatmatches with the receive beam at the terminal device side in thedownlink can also be indicated by an uplink message subsequent to a RApreamble, for example an additional bit or the like, this is one exampleof an explicit manner.

A first aspect in accordance with the present disclosure, whichprimarily discloses transceiving of a synchronization signal inaccordance with an embodiment herein, is described below in conjunctionwith FIGS. 3A through 14 . According to some embodiments, thesynchronization signal is transmitted from the base station side to theterminal device side by beamforming, and the terminal device receivesthe synchronization signal, and obtains information of the transmit beamused to transmit the synchronization signal by the base station.Thereafter, the terminal device feeds back the obtained transmit beaminformation back to the base station, whereby the base station can learnfrom the feedback the transmit beam which it uses to transmit thesynchronization signal, for subsequent communication use. According tosome embodiments, the operations according to the first aspect of thepresent disclosure can be performed by electronic devices for the basestation side and the terminal device side. The operation according tothe first aspect of the present disclosure will be described in detailbelow.

Example of Electronic Device for Base Station Side

FIG. 3A illustrates an exemplary electronic device for a base stationside in accordance with an embodiment herein, where the base station canbe used in various wireless communication systems. The electronic device300A shown in FIG. 3A can include various units to implement the firstgeneral aspect in accordance with the present disclosure. As shown inFIG. 3A, the electronic device 300A may include, for example, asynchronization signal transmitting unit 305 and a feedback acquisitionunit 310. According to one implementation, the electronic device 300Amay be, for example, the base station 120 in FIG. 1 or may be part ofthe base station 120, or may also be a device for controlling a basestation (for example, a base station controller) or a device for a basestation or a portion of them. The various operations described below inconnection with the base station can all be implemented by units 305,310 or other units of electronic device 300A.

In some embodiments, the synchronization signal transmitting unit 305can be configured to transmit a synchronization signal to the terminaldevice by beamforming, to indicate information of the transmit beam usedto transmit the synchronization signal. The synchronization signaltransmitting unit 305 can repetitively transmit the synchronizationsignal to the terminal device using different transmit beams based onthe transmit beam configuration, the synchronization signal includesinformation of the transmit beam used to transmit the synchronizationsignal. In one example, the synchronization signal per se may include orindicate information of the transmit beam used to transmit thesynchronization signal. In another example, transmission resources, suchas frequency and time parameters, used to transmit the synchronizationsignal may indicate the above-described information of the transmitbeam. In some embodiments, information of the transmit beam can includetransmit beam IDs, each transmit beam ID corresponds to a particularoriented transmit beam.

In some embodiments, the feedback acquisition unit 310 can be configuredto obtain feedback from the terminal device, the feedback includesinformation of the transmit beam for using in transmit beam management.The transmit beam corresponding to information of the transmit beam maybe a transmit beam that matches with reception at the terminal device orthat is with a highest degree of such matching. In one example, thefeedback acquisition unit 310 can directly receive feedback sent fromthe terminal device. In another example, the feedback acquisition unit310 can obtain feedback of the terminal device from another base stationvia, for example, the Xn interface, such as from the primary basestation in the dual connectivity scenario described above. The feedbackand the process of providing feedback will be described in detail below.The electronic device 300A can obtain information of the transmit beam,such as a transmit beam ID, from the feedback. The transmit beamrepresented by the transmit beam ID is a transmit beam that matches withreception at the terminal device, and the electronic device 300A canmanage the transmit beam matching with each terminal device, for usingthe transmit beam in subsequent downlink communication with the terminaldevice.

Example of Electronic Device for Terminal Device Side

FIG. 3B illustrates an exemplary electronic device for a terminal deviceside in accordance with an embodiment herein, where the terminal devicecan be used in various wireless communication systems. The electronicdevice 300B shown in FIG. 3B can include various units to implement thefirst general aspect in accordance with the present disclosure. As shownin FIG. 3B, in one embodiment, the electronic device 300B may include asynchronization signal receiving unit 325 and a feedback providing unit330. According to one implementation, the electronic device 300B may be,for example, the terminal device 110 of FIG. 1 or may be part of theterminal device 110. The various operations described below inconnection with the terminal device can all be implemented by units 325,330 or other units of the electronic device 300B.

In some embodiments, the synchronization signal receiving unit 325 canbe configured to receive a synchronization signal to obtain informationof the transmit beam used to transmit the synchronization signal by thebase station based on the received synchronization signal. In oneembodiment, the synchronization signal receiving unit 325 can beconfigured to receive the synchronization signal based on a transmitbeam configuration of the base station side of the wirelesscommunication system. Alternatively or additionally, the synchronizationsignal receiving unit 325 can obtain the above-described information ofthe transmit beam based on a transmission resource, such as time orfrequency parameters, used to transmit the synchronization signal. Insome embodiments, information of the transmit beam can include atransmit beam ID.

In some embodiments, the feedback providing unit 330 can be configuredto provide feedback to the base station, and the feedback can include orindicate information of the transmit beam for being used by the basestation in transmit beam management. In one example, the transmit beamcorresponding to the feedback information of the transmit beam is thetransmit beam that matches with reception at the electronic device 300Bor that is with a highest degree of such matching (e.g., determinedbased on synchronization signal transceiving). In one example, feedbackproviding unit 330 can send the feedback directly to the base stationthat has transmitted the synchronization signal to electronic device300B. In another example, feedback providing unit 330 can forward thefeedback to the base station via another base station (e.g., via theprimary base station in the dual connectivity scenario).

A synchronization signal and its transceiving according to an embodimentherein will be described in detail below, wherein the synchronizationsignal can include or indicate information of the transmit beamtransmitted by a base station. For example, the synchronization signalper se may indicate information of the transmit beam which transmits thesynchronization signal by utilizing different synchronization sequencesor by including different additional bits, or the particulartransmission mode of the synchronization signal can indicate informationof the transmit beam which transmits the synchronization signal.

Example of Synchronization Signal

According to an embodiment herein, the synchronization signalstransmitted by the base station can be of different types. Each type ofsynchronization signal can generally include correspondingsynchronization signal sequence. In some embodiments, thesynchronization signal can include at least a PSS and a SSS. In otherembodiments, the synchronization signal may further include a tertiarysynchronization signal (TSS). In general, a synchronization signal needsto be transmitted on a time-frequency domain resource. In someembodiments, a plurality of synchronization signals can be continuous intime domain; in other embodiments, the plurality of synchronizationsignals can be discontinuous in time domain. In some embodiments, theplurality of synchronization signals can be continuous in frequencydomain; in other embodiments, the plurality of synchronization signalscan be discontinuous in frequency domain.

FIGS. 4A-4D illustrate exemplary time-frequency domain resources for asynchronization signal in accordance with an embodiment herein. In someembodiments, the frequency domain resources used for transmitting thesynchronization signal can be relatively fixed, such as can be a numberof resource blocks or subcarriers in the center of the frequency band,and the respective time domain resources can be located at predeterminedpositions in the downlink frame. As shown in FIGS. 4A and 4B, taking theframe structure in the LTE system as an example, the frequency domainresources used for transmitting the PSS and the SSS can be a number of(for example, six) resource blocks (not specifically shown) in thecenter of the frequency band, and the time domain resource fortransmitting the PSS can be located at one OFDM symbol of a first timeslot of a subframe, the frame number of which is 5, in one downlinkframe, and the time domain resource for transmitting the SSS can belocated at another OFDM symbol of the first time slot of the subframe inthe downlink frame. In the example of FIG. 4A, the PSS and the SSS arediscontinuous in time domain. FIG. 4B is similar to FIG. 4A, with theexception that the PSS and the SSS in the example of FIG. 4B arecontinuous in time domain. As is known, the frames including a pluralityof subframes shown in FIGS. 4A and 4B are repeated in time domain, andeach frame can have a radio frame number, which number has a certainperiod. For example, in the LTE system, the radio frame number is alsoreferred to as system frame number (SFN), which has a period of 1024,and each frame can be identified within a range of 1024 frames.

As shown in FIG. 4C, one frequency domain resource block can be used totransmit the PSS, and another frequency domain resource block can beused to transmit the SSS. In the example of FIG. 4C, the PSS and the SSSare discontinuous in frequency domain. See FIG. 4D (i.e., arrangements(1) through (5)) for more arrangements of different types ofsynchronization signals over time-frequency domain resources.

Further, as shown in FIGS. 4A and 4B, time domain resources fortransmitting different types of synchronization signals can have acertain positional relationship. The positional relationship can includethe order between time domain resources. For example, in FIG. 4A, thesymbol for the SSS precedes the symbol for the PSS; whereas in FIG. 4B,the symbol for the PSS precedes the symbol for the SSS. Alternatively oradditionally, the positional relationship can include an intervalbetween time domain resources. For example, the symbols for the PSS andthe SSS in FIG. 4A are separated by 3 symbols; whereas the symbols forthe PSS and the SSS in FIG. 4B are not separated (0 symbolstherebetween). Although not specifically described herein, it should beunderstood that frequency domain resource blocks for transmittingdifferent types of synchronization signals can also have similarpositional relationships. Moreover, the positional relationship can alsobe a combined time domain and frequency domain positional relationship.In some embodiments, system information can be represented by relativepositions of different types of synchronization signals in the time orfrequency domain. In one example, the system information can include atleast one of a duplex type of a wireless communication system and adifferent cyclic prefix length. For example, the order of the PSS andthe SSS can represent a duplex type (e.g., the PSS preceding representsTDD, and succeeding represents FDD), and the intervals between the PSSand the SSS can represent different cyclic prefix lengths (e.g., aninterval of 3 symbols represents an extended cyclic prefix, etc.).

FIG. 4D illustrates five exemplary arrangements of synchronizationsignals over time-frequency domain resources (horizontal directionrepresents the time domain and vertical direction represents thefrequency domain). As described previously, the positional relationship(time domain, frequency domain, or a combination thereof) betweendifferent types of synchronization signals in these arrangements canrepresent different system information. The exemplary arrangements inFIG. 4D have in common that individual synchronization signals arecontinuous, i.e., continuous in the time domain, frequency domain ortime-frequency domain. It can be considered that these different typesof continuous synchronization signals form a synchronization signalblock (SS Block, SSB). Synchronization signals can be carried in eachsynchronization signal block and transmitted repetitively. For a givenfrequency band, the synchronization signal block can correspond to NOFDM symbols based on default subcarrier spacing, where N is a constant.The terminal device can obtain at least a slot index and a symbol (e.g.,OFDM symbol) index in the radio frame from the synchronization signalblock. In one example, the synchronization signal block can also includea channel for broadcasting from which the terminal device obtains theradio frame number. For example, in arrangement (5), the synchronizationsignal block can also include a PBCH broadcast channel.

According to some embodiments herein, the synchronization informationcan include information of the transmit beam used to transmit thesynchronization signal by the base station. For example, differentsynchronization signal blocks can include different synchronizationsignal content (e.g., different synchronization signal sequences ordifferent additional information bits) to indicate information of thetransmit beam (transmit beam ID) used to transmit the synchronizationsignal block.

Example of Transmission Time Window for SynchronizationSignals/Synchronization Signal Blocks

In general, synchronization signals can be transmitted in specific timewindows in the downlink frames, which time windows can be arranged incertain time periods or in a time pattern. These time windows cancorrespond to particular transceiving occasions of the synchronizationsignals/synchronization signal blocks. In an embodiment herein, sincebeamforming is used to transmit synchronization signals, moretransmission windows for synchronization signals are needed for: 1)transmitting using a plurality of different beams, and 2) repetitivelytransmitting using a single beam. Taking the transmission of SS blocksas an example, in some embodiments, time windows for a plurality of SSblocks can be scattered, i.e., discontinuous in the downlink frame. Onerespective example is seen from FIG. 5A. As shown in FIG. 5A, timewindows for transmitting SS blocks are arranged at a certain period, andeach SS block can comprise, for example, a PSS, a SSS, and a broadcastchannel.

In some embodiments, multiple (e.g., 2, 4, 8, 12, 16) SS blocks can bemade concentrated (i.e., continuous) in the time domain to form asynchronization signal burst (SS Burst), to transmit synchronizationsignals using transmit beamforming. In the time domain, the SS burst caninclude a plurality of continuous SS blocks. In one example, the lengthof the SS burst can be represented by the number of SS blocks includedtherein. Multiple SS bursts can be spaced by a certain interval in thetime domain. Since a SS bursts can concentrate a plurality of SS blocks,enabling base stations and terminal devices to complete beam scanningfaster while transceiving synchronization signals. One example of a SSburst is seen in FIG. 5B, where the length of the SS burst is 12. Asshown in FIG. 5B, the 12 time windows for transmitting SS blocks areconcentrated with each other to form one larger time window for the SSburst, and multiple larger time windows can be arranged in a certainperiod (such as SS burst period). Each SS block can also include, forexample, a PSS, a SSS, and a broadcast channel.

In the wireless communication system, time windows for transmitting thesynchronization signal are often designated to correspond to specifictime parameters of the downlink frame. Thus, the SS burst, SS blocks,and synchronization signal in FIGS. 5A and 5B can be associated with thetime parameters of the downlink frame via a time window, and exampletime parameters can include an OFDM symbol index, slot index in a radioframe and radio frame number, etc. For example, it can be determinedthat the SS burst, SS block or synchronization signal is located in acertain radio frame, and is specifically located at a certain OFDMsymbol of a certain slot. That is, the terminal device can identify oneor more of the OFDM symbol index, slot index in the radio frame, and theradio frame number based on reception of the SS block or thesynchronization signal.

According to some embodiments herein, the manner in which thesynchronization signal is transmitted (e.g., time window fortransmission, time parameters, etc.) can indicate information of thetransmit beam used to transmit the synchronization signal. For example,in some embodiments, these time parameters can be combined with atransmit beam configuration for identifying (e.g., by a terminal device)the transmit beam used to transmit the synchronization signal.

Synchronous Signals Transmission at Base Station Side

According to some embodiments, the base station can transmitsynchronization signals based on a transmit beam configuration. Asdescribed previously, the repetition pattern of multiple transmit beamsat the base station side can be represented by the transmit beamconfiguration. In general, in order to represent the repetition patternof transmit beams, the transmit beam configuration may include orindicate information of at least two aspects, namely a number oftransmit beams and a number of times each transmit beam can be used torepetitively transmit (e.g., synchronization signals). In someembodiments, the transmit beam configuration can also specify timeparameters for at least one synchronization signal transmission.

In some embodiments, the transmit beam configuration can specify anumber of transmit beams that can be used to transmit synchronizationsignals by the base station and a number of times each transmit beam canbe consecutively used to transmit. FIGS. 6A and 6B illustrate anexemplary transmit beam configuration at the base station side inaccordance with an embodiment herein. As shown in FIG. 6A, the transmitbeam configuration 600A specifies that the base station side has 4transmit beams TX_B1 to TX_B4 for transmitting synchronization signals,and can consecutively use each of the transmit beams three times totransmit synchronization signals. As shown in FIG. 6B, the transmit beamconfiguration 600B specifies that the base station side has 12 transmitbeams TX_B1 to TX_B12 for transmitting synchronization signals, and canonly use each of the transmit beams once to transmit synchronizationsignals. In some cases, the transmit beam configuration can berepresented in the form of N (beams)×M (times). For example, theexemplary transmit beam configuration of four different transmit beams,each transmit beam repeated three times in FIG. 6A, can be referred tobriefly as 4 (beams)×3 (times) configuration. Similarly, the exampleconfiguration in FIG. 6B can be referred to briefly as 12×1configuration. These transmit beam configurations are only examples. Invarious embodiments, the number of transmit beams can be any number, andthe number of repetitions can be one or more times.

In a corresponding embodiment, electronic device 300A can transmit asynchronization signal using each of a plurality (e.g., 4 or 12) oftransmit beams based on the transmit beam configuration, andconsecutively transmit the synchronization signal using each transmitbeam for a specified number of times (for example, 3 times or 1) (i.e.,transmit beam scanning).

According to some embodiments herein, it is also possible tosequentially transmit the synchronization signal once using eachtransmit beam, and then repeat the process for a specified number oftimes, thereby performing transmit beam scanning.

In some embodiments, the transmit beam configuration can specify anumber of transmit beams of different levels that can be used totransmit the synchronization signal by the base station and a number oftimes each transmit beam of different levels can be consecutively usedto transmit. FIG. 6C illustrates an exemplary transmit beamconfiguration in the case of hierarchical transmit beams at the basestation side, in accordance with an embodiment herein. It is assumedthat there are four first level transmit beams at the base station side,and each first level transmit beam has two second level transmit beams.The first level of the transmit beam configuration can be, for example,as shown in FIG. 6A, and the second level of the transmit beamconfiguration can be, for example, as shown in FIG. 6C. The second levelof the transmit beam configuration 600C specifies eight second leveltransmit beams TX_B1,1 to TX_B4,2 for transmitting synchronizationsignals, and each of the second level transmit beams can beconsecutively used for three times to transmit synchronization signals.In some cases, the hierarchical transmit beam configuration can also berepresented in the form of N (beams)×M (times). For example, the firstlevel of the transmit beam configuration of FIG. 6C can be representedas 4 (beams)×3 (times) configuration, and the second level of thetransmit beam configuration can be represented as 2 (beams)×3 timesconfiguration (where “2” second level transmit beams correspond to asingle first level transmit beam) or 8×3 configuration (where “8” secondlevel transmit beams correspond to all the first level transmit beams).

In a corresponding embodiment, electronic device 300A can be configuredto transmit a synchronization signal using each of said different levelsof transmit beams and transmit the synchronization signal byconsecutively using each transmit beam for specified number of times.

In some embodiments, the transmit beam configuration can also indicatecorrespondence between transmit beams at the base station side and aplurality of time windows for synchronization signals, such as byindicating correspondence between a particular transmission of aparticular transmit beam and a time window for a synchronization signal.For example, transmit beam configuration 600A can specify a time windowfor a first transmission of the synchronization signal using thetransmit beam TX_B1 (e.g., specify time parameters of the time windowincluding a particular frame, subframe, time slot, and/or OFDM symbol,etc.). At this time, the electronic device 300A can transmit thesynchronization signal using the transmit beam TX_B1 based on the timewindow/time parameters, and continue with the subsequent transmissionsbased on the arrangement of the time windows for synchronization signalsand the transmit beam configuration. Accordingly, the electronic device300B can determine the transmit beam used to transmit thesynchronization signal based on the time window/time parameters when thesynchronization signal is successfully received and on the transmit beamconfiguration. Specific examples can be referred to the followingdescription of FIGS. 7A to 7D.

FIGS. 7A to 7D illustrate correspondence between transmit beams and SSblocks (or synchronization signals), according to an embodiment herein.FIGS. 7A and 7B illustrate exemplary correspondences in a configurationof 4 (beams)×3 times, in which FIG. 7A corresponds to a case where SSblocks are temporally dispersed, and FIG. 7B corresponds to a case whereSS blocks form SS bursts.

In FIG. 7A, based on the correspondence between transmit beams at thebase station side and a plurality of time windows for thesynchronization signal, on each of the three SS block positions of thefirst group, the first transmit beam is used to transmit the SS block.On each of the three SS block positions of the second group, the secondtransmit beam is used to transmit the SS block. Next, on each of the SSblock positions of the third group and the fourth group, the third andfourth transmit beams are used, respectively, to transmit the SS block.It is to be noted that FIG. 7A illustrates only one cycle of theexemplary beam configuration, and the above arrangement can be repeatedat a later time to transmit the synchronization signals.

In FIG. 7B, the SS blocks are arranged as SS bursts in time domain, andthe SS bursts can be transmitted based on a certain period. Thereto, thelength of the SS burst is exactly 12 SS blocks, so it matches with the12 transmissions of synchronization signal in the 4×3 configuration. Insome embodiments, there may be cases where the length of the SS burstdoes not exactly match with the transmit beam configuration (e.g., SSbursts of length 15 may not exactly match with the configuration of4×3), and this matching can be obtained by pre-configurations. In FIG.7B, for the first SS burst, on each of the three SS block positions ofthe first group, the first transmit beam is used to transmit the SSblocks. On each of the three SS block positions of the second group, thesecond transmit beam is used to transmit the SS blocks. Next, on the SSblock positions of the third group and the fourth group, the third andfourth transmit beams are used, respectively, to transmit the SS blocks.Thereafter, for the following SS bursts, the above arrangement isrepeated to transmit the synchronization signals.

In addition to the configuration of 4 (beams)×3 (times), differenttransmit beam configurations can be selected as needed, for example, 6(beams)×3 (times), 8 (beams)×2 (times), and the like. In particular, inthe case of SS bursts, for example for a SS burst of length 12, therecan be configurations of, for example, 2×6, 3×4, 6×2, 12×1. Moreover,there can be other lengths of SS bursts and corresponding transmit beamconfigurations (e.g., configuration of 5×3, SS bursts of length 15).

FIGS. 7C and 7D illustrate a configuration of 12 (beams)×1 (times). Forthe understanding of FIGS. 7C and 7D, reference can be made to the abovedescription of FIGS. 7A and 7B, and description thereof will not berepeated herein. The choice of the transmit beam configurations is basedon, for example, the number of transmit beams supported by the basestation, the number of transmit beams supported by the terminal device,and the like. For example, in the case where the cell coverage islarger, the synchronization signal is required to be able to cover afurther distance, thus a larger transmit beamforming gain at the basestation side is required, and each transmit beam can be relativelynarrow, and accordingly, the larger the number of transmit beams can be.At this time, it is possible to select, for example, a configuration of6×2 or 12×1. In contrast, in the case where the cell coverage issmaller, each transmit beam can be relatively wide, and accordingly, theless the number of transmit beams can be. In the case where there aremore of receive beams at the terminal device, it is possible to select,for example, 2×6, 3×4 configurations. In the case where the terminaldevice uses a full-width receive beam, it is possible to select a 12×1configuration. Since the synchronization signal transmit beamconfiguration of the base station is cell-specific rather than terminaldevice-specific, in some examples the base station can collect receivebeamforming capabilities of its already served terminal devices, and setthe transmit beam configuration in accordance with a fairness principle.

As described above, in the case where the correspondence betweentransmit beams at the base station side and time windows for thesynchronization signal is known, the transmit beam used to transmit thesynchronization signal can be determined based on the time windows/timeparameters when the synchronization signal is successfully received andthe transmit beam configuration. Taking FIG. 7A as an example, it isassumed that the time parameter t1 corresponding to the first transmitbeam 701 is known, and the terminal device receives the synchronizationsignal from the SS block and determines the time parameter t2 of thetransmit beam 702. Assuming that a period of the SS blocks is T, then(t1−t2)/T represents how many transmit beam transmissions the transmitbeam 702 is after the transmit beam 701. In the example of FIG. 7A, theterminal device can determine that the transmit beam 702 is the ninthtransmit beam transmission after the transmit beam 701, and inconsideration the fact that there are four beams and each beam repeatsthree times in the 4×3 configuration, it can be determined that transmitbeam 702 is the fourth transmit beam. The method is applicable to FIG.7B as well, except that the periods to be considered include a period ofthe SS burst and a period of the SS blocks within the SS burst.

Synchronization Signal Reception at Terminal Side

According to some embodiments, the terminal device can receivesynchronization signals from the base station side in a variety of ways.According to one embodiment, if the terminal device does not usebeamforming to receive the synchronization signal (i.e., using afull-width receive beam), the electronic device 300B at the terminaldevice side just needs to receive, by using the full-width beam, thesynchronization signals transmitted through different transmit beams bythe base station. According to one example, for specified times ofconsecutive transmissions of each transmit beam, all transmissions ofthe transmit beam, or just one transmission (such as the firsttransmission) of the transmit beam can be received by using thefull-width beam. According to another example, for a specified number oftransmissions sequentially transmitted by all transmit beams, alltransmissions of the transmit beams, or just one round of transmissions(such as a first round of transmissions) of all transmit beams can bereceived by using the full-width beam.

According to another embodiment, if the terminal device needs to usereceive beamforming, then for a specified number of transmissions by thebase station using each transmit beams, the electronic device 300B atthe terminal device side can be configured to receive synchronizationsignals by using different receive beams (i.e., the receive beamscanning). As one example, for a specified number of consecutivetransmissions by the base station using each transmit beam, differentreceive beams can be used to receive the synchronization signalstransmitted by the same transmit beam. According to another example, fora specified number of transmissions sequentially transmitted by alltransmit beams, a same receive beam can be used to receive all transmitbeams in a single round of sequential transmissions, or differentreceive beams are used to receive the transmit beams until each receivebeam can receive all the transmit beams. In the above embodiment, in thecase where the receive beam scanning is required, the electronic device300B at the terminal device side needs to have known or be able to knowthe transmit beam configuration, thereby determining its own receivebeam arrangement.

The receive beam arrangements employed by the terminal device when theterminal device receives synchronization signals will be exemplarilydescribed below.

As described previously, the terminal device may or may not use receivebeamforming to receive synchronization signals transmitted by the basestation via transmit beamforming. FIG. 8A illustrates an exemplaryreceive beam arrangement of a terminal device in a 4×3 transmit beamconfiguration. The receive beam arrangements 1 and 2 in FIG. 8Acorrespond to the case where the terminal device does not use receivebeamforming to receive synchronization signals. Then, electronic device300B can generally use receive beam arrangement 1, that is, use afull-width receive beam (e.g., RX_B1) to receive each transmission ofeach transmit beam. The advantage of the receive beam arrangement 1 isthat, a plurality of transmissions by each transmit beam can bereceived, and diversity gain can be obtained. When receiving thesynchronization signals, the electronic device 300B can perform acorrelation operation based on the content of the SS blocks, and thetransmit/receive beams pair with a highest correlation or a correlationhigher than a certain predetermined threshold is the matching transmitbeam. For example, when the correlation in receiving the synchronizationsignal transmitted by the transmit beam 2 is higher than that in thecase of other transmit beams, the transmit beam 2 can be considered tomatch with the full-width receive beam. In one preferred specificexample, considering that the number of sequences in the PSS sequenceset is much smaller than the number of sequences in the SSS sequenceset, the electronic device 300B is designed to first perform acorrelation operation between the PSS sequence in the SS block carriedby the received transmit beam and each sequence in the pre-stored set ofPSS sequences, and determine the matching transmit beam (and thematching PSS sequence) therein according to the degree of thecorrelation of the PSS sequence carried by each transmit beam, and thenperform a correlation between the SSS sequence in the SS block carriedby the matching transmit beam and each sequence in the set of SSSsequences to determine a matching SSS sequence, and the electronicdevice 300B then calculates to obtain the physical cell identity (PCI)of the corresponding cell according to the matching PSS sequence and theSSS sequence, for example, PCI=PSS+3*SSS, and determines the downlinkreference signal structure according to the PCI to decode the PBCH. Insome examples, the PSS values are 0 . . . 2 (refers to 3 different PSSsequences), and the SSS values are 0 . . . 167 (refers to 168 differentSSS sequences). The range of PCIs that can be obtained by using aboveformula is from 0 . . . 503, so there are 504 PCIs in the physicallayer. In the example in which synchronization signals further includesthe TSS, the matching of the TSS sequences are performed lastly and thethe PCI is calculated according to a redesigned PCI calculation formula(the specific formula is not the technical problem intended to be solvedby the present disclosure, and is not described herein). Thereby, thecomplexity of the synchronization scheme based on the present disclosurecan be effectively reduced, and in particular, the number of SSSS in thenext generation cellular network may increase to thousands, and then thetechnical effect of the preferred example is particularly remarkable.Where the electronic device 300B is aware of the transmit beamconfiguration of the base station, only part of transmissions inmultiple repetitive transmissions of each transmit beams may bereceived. For example, electronic device 300B can use receive beamarrangement 2, that is, for multiple transmissions of each transmitbeam, a full-width receive beam (e.g., RX_B1) is used to receive onlyonce (e.g., only receive the first transmission). The advantage of thereceive beam arrangement 2 is that the receiving resources (e.g., powerconsumption, etc.) of the terminal device can be saved.

The receive beam arrangements 3 and 4 in FIG. 8A correspond to the caseswhere the terminal device receives the synchronization signals using 2or 3 different receive beams, respectively. Then, for multipletransmissions of each transmit beam, the electronic device 300B needs toreceive using different receive beams. To this end, the electronicdevice 300B needs to know the transmit beam configuration of the basestation to arrange corresponding receive beams. In the receive beamarrangement 3 or 4, since the electronic device 300B knows that eachtransmit beam is repeated 3 times, it is possible to arrange its ownreceive beams in these 3 repetitions so that each receive beam is usedat least once, thereby realizing the purpose of beam scanning. FIG. 8Aillustrates only one cycle of transmissions of different transmit beams,which can be followed by the next cycle.

For the above 4×3 transmit beam configurations, when the terminal devicehas more than 3 receive beams, the scan of all receive beams cannot becompleted within one cycle of different transmit beam transmissions.However, since the electronic device 300B knows the transmit beamconfiguration, it can arrange remaining receive beams for scanning inthe next cycle. In light of the teachings herein, those skilled in theart can contemplate various variations of the receive beam arrangementsto achieve beam scanning, all of which are within the scope of thepresent disclosure.

In addition, FIG. 8A is merely a schematic arrangement of time windowsthat can represent the relative positions of the various time windows,but not indicate their exact positions in the downlink frame. Forexample, multiple discontinuous time windows can be used as in FIGS. 7Aand 7C, or multiple continuous time windows can be used as in FIGS. 7Band 7D. Further, the time windows in the various figures herein and thespaced therebetween are merely illustrative and not necessarily drawn toscale.

It should be understood that in a hierarchical transmit beamconfiguration, it can be considered that FIG. 8A show a first leveltransmit beams and corresponding various receive beam arrangements. Thefirst level transmit beams can be followed by a second level transmitbeams. FIG. 8B illustrates a second level of transmit beam configurationand an exemplary receive beam arrangement of the terminal device. Thefirst level configuration of the hierarchical transmit beamconfiguration can be the above 4×3 transmit beam configuration, and thesecond level configuration can be 2×3 transmit beam configuration, i.e.,each coarse transmit beam corresponds to two fine transmit beams, eachof which is repeated three times (for simplicity, only the fine beamscorresponding to the first two coarse beams are shown). In one example,after transmissions using the first level transmit beams as that in FIG.8A, the transmission can then be done using the second level transmitbeams, as shown by the transmit beam configuration in FIG. 8B. In FIG.8B, individual fine transmit beams corresponding to each coarse transmitbeam are successively repeated up to the number of times indicated inthe transmit beam configuration. For example, the fine transmit beamTX_B1,1 corresponding to the coarse transmit beam TX_B1 is firstrepeated 3 times, and then TX_B1, 2 is also repeated 3 times, therebycompleting the scanning of the fine transmit beam corresponding to thefirst coarse transmit beam TX_B1. Next, scanning of the fine transmitbeams corresponding to the next coarse transmit beam is sequentiallyperformed.

Similar to that described in FIG. 8A, in FIG. 8B, the receive beamarrangements 1 and 2 correspond to the cases where the terminal devicedoes not use receive beamforming. Then, the electronic device 300B canuse the receive beam arrangement 1, i.e., use a full-width receive beam(e.g., RX_B1) to receive each transmission of each transmit beam. Theadvantage of the receive beam arrangement 1 is that, a plurality oftransmissions by each transmit beam can be received, and diversity gaincan be obtained. When receiving the synchronization signal transmittedby each of the fine transmit beams, the electronic device 300B canperform a correlation operation based on the content of the SS blocks,and the transmit/receive beams pair with a highest correlation or acorrelation higher than a certain predetermined threshold is thematching transmit/receive beams pair. For example, when the correlationin receiving the synchronization signal transmitted by TX_B2, 1 ishigher than that in the case of other transmit beams, TX_B2, 1 can beconsidered to match with RX_B1. In the case where the electronic device300B knows the transmit beam configuration of the base station, theelectronic device 300B can also use the receive beam arrangement 2, thatis, for multiple repetitive transmissions of each transmit beam, onlypart of transmissions are received. For example, a full-width receivebeam (e.g., RX_B1) can be used to receive only once (e.g., only receivethe first transmission). The advantage of the receive beam arrangement 2is that the receiving resources (e.g., power consumption, etc.) of theterminal device can be saved.

The receive beam arrangements 3 and 4 in FIG. 8B correspond to the caseswhere the terminal device receives the synchronization signals using 2or 3 different receive beams, respectively. Then, for multipletransmissions of each fine transmit beam, the electronic device 300Bneeds to receive using different receive beams. To this end, theelectronic device 300B needs to know the transmit beam configuration ofthe base station to arrange corresponding receive beams. In the receivebeam arrangement 3 or 4, since the electronic device 300B knows thateach fine transmit beam is repeated 3 times, it is possible to arrangeits own receive beams in these 3 repetitions, so that each receive beamis used at least once, thereby realizing the purpose of the beamscanning. FIG. 8B illustrates one cycle of transmissions of differentfine transmit beams. In the case of hierarchical transmit beam scanning,after completing one cycle of fine transmit beam scanning, the nextcycle of coarse transmit beam scanning and fine transmit beam scanningcan be performed. In light of the teachings herein, those skilled in theart can contemplate various variations of the receive beam arrangementsto achieve beam scanning, all of which are within the scope of thepresent disclosure.

It should be understood that in the example of FIG. 8B, 24 (8×3) timewindows are required for all transmit beam scans of the second level tocomplete. Therefore, it may be necessary to complete in two SS bursts oflength 12.

As previously described, the length of the SS burst can be matched withthe transmit beam configuration by pre-configurations such that the fulltransmit beam configuration can be known with knowledge of one of thenumber of transmit beams or the number of repetitions. For example, a SSburst of length 12 matches with the 4×3 configuration described above.In the case of a SS burst of length 12, once it is known that there are4 transmit beams, it can be known that each transmit beam is repeated 3times; vice versa.

Acquisition of Transmit Beam Configuration by Terminal Device

In some embodiments, in order to facilitate reception of thesynchronization signal by the terminal device, the terminal device needsto know the transmit beam configuration of the base station side.However, the terminal device cannot obtain any information about thetransmit beam configuration from the base station by signaling beforesuccessfully receiving the synchronization signal. According to anembodiment herein, the terminal device can obtain the transmit beamconfiguration by at least obtaining the transmit beam configuration viaother base stations, and/or obtaining the transmit beam configuration bytransmitting beam measurements.

According to some embodiments herein, the electronic device 300A for thebase station can be configured to deliver a transmit beam configurationto another base station that serves the terminal device together withthe base station by dual connectivity, the transmit beam configurationcan be indicated to the terminal device by the other base station.

As is known, dual connectivity is a technology that enables a terminaldevice to communicate with a plurality of base stations, therebyincreasing the data rate. For example, the terminal device can maintaina connection with both the first base station and the second basestation. In the process of the first base station communicating with theterminal device, the second base station can be added to form a dualconnectivity as needed (for example, increased data rate is desired),then the first base station becomes the primary node, and the secondbase station becomes the secondary node. In some cases, the primary nodecan be an eNB in an LTE system, and the secondary base station can be acorresponding node in a 5G system, such as a gNB in an NR system.According to an embodiment herein, the adding operation can beimplemented by a secondary node addition operation as follows.

FIG. 9 illustrates exemplary operations of secondary node addition inaccordance with an embodiment herein. In FIG. 9 , the electronic device300A can correspond to a second base station, by these exemplaryoperations, the terminal device forms a dual connectivity with the twobase stations. At 902, the first base station can transmit a secondarynode addition request message to the second base station, to request thesecond base station to allocate radio resources for communicating withthe terminal device. Here, the first base station can indicate theconfiguration for the main cell group (MCG) serving the terminal deviceand the terminal device capability, and can provide measurement resultsfor the cell in a secondary cell group (SCG) of a second base stationthat is required to be added to the terminal device. At 904, the secondbase station can allocate corresponding resources and send a secondarynode addition request ACK to the first base station upon the radioresource management entity grants the resource request. Here, the secondbase station can trigger RA process so that synchronization of radioresource configuration of the secondary node can be performed. Thesecond base station can provide the first base station with new radioresources of the SCG and beam configuration information of the primarycell (PSCell) among the SCG. Of course, in some cases, the beamconfiguration information can also include beam configurationinformation of other cells in the SCG. At 906, the first base stationcan instruct the terminal device to perform RRC connectionreconfiguration and indicate the above transmit beam configuration tothe terminal device. At 908, the terminal device can indicate to thefirst base station that the RRC connection reconfiguration is complete.At 910, the first base station can indicate to the second base stationthat the secondary node reconfiguration is complete. In this way, theterminal device can perform a synchronization process with the PSCell ofthe secondary node based on the obtained transmit beam configurationinformation. The second base station which serves as the secondary nodedoes not need to broadcast system information other than the radio frametiming and the SFN, and system information (initial configuration) isprovided to the terminal device through the dedicated RRC signaling ofthe first base station which serves as the primary node. The radio frametiming and SFN of the SCG can be obtained from at least thesynchronization signals of the PSCell (e.g., PSS, SSS, and PBCH).

In some embodiments, the first base station may not be limited to aneNB, and the second base station may not be limited to a gNB. Forexample, the first base station and the second base station can be anybase stations belonging to the same wireless communication system ordifferent wireless communication systems. In some examples, the firstbase station described above may be a base station belonging to awireless communication system of a prior generation.

According to some embodiments herein, the terminal device can include anomnidirectional antenna. Before receiving the synchronization signalsusing different receive beams, the electronic device 300B can beconfigured to receive synchronization signals without using beamformingto obtain a transmit beam configuration at the base station side.

Referring to FIG. 2B, it is assumed that the electronic device 300Breceives, with a full-width receive beam, synchronization signalstransmitted by the base station side using different transmit beams. Forthe electronic device 300B, different transmit beams at the base stationside mean different reception performance. In the 3×3 configuration, thereception performance at the electronic device 300B can be as shown inFIG. 10 . Therein, A, B, and C represent different receptionperformance, respectively. By measuring for a certain period of time, itis possible to determine that there are three transmit beams based onthree types of reception performances existing, and it is possible todetermine that each transmit beam is repeated three times based on threerepetitions of each type of reception performance. In the case where thetransmit beam configuration is mated with the SS burst, the transmitbeam configuration can be determined based on the length of the SS burstcombined with one of the number of different reception performances andthe times of repetitions of each reception performance. In this example,in the case where the length of the SS burst is 9, it can be determinedthat each transmit beam is repeated (9/3)=3 times based on three typesof reception performances existing, or it can be determined that thereis (9/3)=3 transmit beams based on each type of reception performance isrepeated 3 times.

Indication and Feedback of Transmit Beams

In an embodiment herein, transmitting a synchronization signal throughtransmit beamforming can be used to indicate information of the transmitbeam used to transmit the synchronization signal, such as a transmitbeam ID. The transmission of the synchronization signal can indicate orinclude the transmit beam ID by at least one of the followings.

As previously described, the synchronization signal can include asynchronization sequence. In one embodiment, the synchronizationsequence per se can represent a transmit beam ID. For example, thesynchronization sequences can be divided into groups, and allsynchronization sequences in a same group can represent a same transmitbeam. Taking the PSS in the LTE system as an example, there can bemultiple Zadoff-Chu sequences of length 63 in the system. For 4×3transmit beam configurations, these Zadoff-Chu sequences can be divided(e.g., equally divided) into 4 groups as shown in FIG. 11A, and thesequences in each group can represent one of 4 transmit beams. Forexample, any sequence in the first group of sequences (1st to N/4thsequences) can represent the transmit beam ID 1. When the electronicdevice 300A transmits a synchronization signal using this transmit beam,the synchronization sequence included in the synchronization signal canbe any sequence in the first group. Thus, when receiving thesynchronization signal, the electronic device 300B can determine, basedon the synchronization sequence in the synchronization signal, that IDof the transmit beam used to transmit the synchronization signal is 1.Of course, in such an embodiment, the base station and the terminaldevice are required to agree upon the correspondence between each groupof synchronization sequences and transmit beams (for example, specify incommunication protocols and pre-store the correspondence into the chipsof both communicating parties).

In one embodiment, in addition to the synchronization sequence, thesynchronization signal also includes additional information bits, whichcan represent the transmit beam ID. As shown in FIG. 11B, for 4×3configuration for transmit beam, additional bits 00, 01, 10, 11 can bedesignated to represent one of the 4 transmit beams, respectively. Forexample, an additional information bits 00 can represent the transmitbeam ID 1. When the electronic device 300A transmits a synchronizationsignal using this transmit beam, the synchronization signal can includethe additional information bits 00. Thus, when receiving thesynchronization signal, the electronic device 300B can determine, basedon the additional bits 00 in the synchronization signal, ID of thetransmit beam used to transmit the synchronization signal to be 1. Insuch an embodiment, similarly, the base station and the terminal deviceare required to agree upon the correspondence between the additionalbits and the transmit beams.

In one embodiment, the transmit beam ID can be represented by timewindows/time parameters where the synchronization signal is located. Forexample, the electronic device 300B can determine the transmit beam IDof the matching transmit beam based on the time parameters of thesynchronization signal transmitted by the matching transmit beam and thetransmit beam configuration (i.e., the number of transmit beams and thenumber of repetitions). A specific example can be seen in thedescription of FIG. 7A.

In various embodiments, after determining the transmit beam ID of thematching transmit beam, the terminal device can feed back the transmitbeam ID to the base station in various suitable manners. For example,after a dual connectivity is established with two base stations via theprocess of FIG. 9 and the base station serves as the secondary node andthe other base station serves as the primary node, the terminal devicecan provide the transmit beam ID to the base station via the primarynode.

According to some examples, a matching transmit beam at the base stationside can be indicated in implicit or explicit manners to feed it back tothe base station. According to some examples, as an explicit manner, thetransmit beam ID can be indicated by additional bits in the feedbackfrom the terminal device to the base station. According to someexamples, as an implicit manner, feedback can be done in accordance withspecific transmission time windows, and the transmit beam can be knownfrom the correspondence between the transmission time windows and thebeams.

This feedback can be included in the RA process performed by theterminal device. Of course, according to some embodiments, the feedbackrelated to the transmit beam at the base station side can be transmittedseparately from the RA preamble, for example, before or after the RApreamble. This feedback operation will be described in detail later inconjunction with the RA process.

Exemplary Method

FIG. 12A illustrates an example method for communication in accordancewith an embodiment herein. As shown in FIG. 12A, the method 1200A caninclude repetitively transmitting a synchronization signal to a terminaldevice by using different transmit beams based on a transmit beamconfiguration, where the synchronization signal includes information oftransmit beam used to transmit the synchronization signal (block 1205).The method also includes obtaining feedback from the terminal device,where the feedback comprises information of the transmit beam for beingused in transmit beam management (block 1210). The method can beperformed by the electronic device 300A, and detailed example operationsof the method can be referred to the above description of operations andfunctions performed by the electronic device 300A, which are brieflydescribed as follows.

In one embodiment, the transmit beam corresponding to the information oftransmit beam fed back from the terminal device is a transmit beam witha highest degree of reception matching with the terminal device.

In one embodiment, the transmit beam configuration specifies a number ofa plurality of transmit beams that the can be used to transmit thesynchronization signal by the base station and a number of times eachtransmit beam can be consecutively used to transmit, and the methodfurther comprises transmitting the synchronization signal by using eachtransmit beam of the plurality of transmit beams, and transmitting thesynchronization signal by using each transmit beam consecutively for thenumber of times.

In one embodiment, the transmit beam configuration specifies a number oftransmit beams of different levels that can be used to transmitsynchronization signal by the base station and a number of times eachtransmit beam of different levels can be consecutively used to transmit,the method further comprises transmitting the synchronization signal byusing each transmit beam of the plurality of transmit beams of differentlevels, and transmitting the synchronization signal by using eachtransmit beam consecutively for the number of times.

In one embodiment, the transmit beam configuration further comprises acorrespondence between the transmit beams at the base station side and aplurality of synchronization signal time windows, and the method furthercomprises transmitting the synchronization signal by using the transmitbeams based on the correspondence between the transmit beams and theplurality of synchronization signal time windows.

In one embodiment, the method further comprises delivering the transmitbeam configuration to another base station that serves the terminaldevice together with the base station through dual connectivity, whereinthe transmit beam configuration is indicated to the terminal device bythe other base station.

In one embodiment, the other base station is a base station in thewireless communication system or a base station in a wirelesscommunication system of a previous generation than the wirelesscommunication system.

In one embodiment, the wireless communication system is a 5G system andthe wireless communication system of the previous generation is an LTEsystem.

In one embodiment, a SS block is formed from different types ofcontinuous synchronization signals, and a SS burst is formed from aplurality of continuous SS blocks.

In one embodiment, the information of transmit beam comprises a transmitbeam ID, and the transmit beam ID is indicated by the synchronizationsignal through one of: the synchronization signal comprises asynchronization sequence, the synchronization sequence per se representsthe transmit beam ID; besides the synchronization sequence, thesynchronization signal comprises additional information bits, and theadditional information bits represent the transmit beam ID; or timeparameters in which the synchronization signal is located.

In one embodiment, the information of the transmit beam with the highestdegree of matching is determined based on the transmit beamconfigurations and the time parameters of the synchronization signaltransmitted by using the transmit beam with the highest degree ofmatching.

In one embodiment, the time parameters comprise indices of OFDM symbols,indices of slots in a radio frame and a radio frame number.

In one embodiment, the synchronization signal comprises a primarysynchronization signal PSS and a secondary synchronization signal SSS,or comprises a primary synchronization signal PSS, a secondarysynchronization signal SSS and a tertiary synchronization signal TSS.

In one embodiment, system information is represented by relativepositions of different types of synchronization signals in a time orfrequency domain, and the system information comprises at least one of:a duplex type of a wireless communication system; or a different cycleprefix length.

FIG. 12B illustrates another example method for communication inaccordance with an embodiment herein. As shown in FIG. 12B, the method1200B can include receiving a synchronization signal based on a transmitbeam configuration at a base station side in a wireless communicationsystem, where the synchronization signal includes information of thetransmit beam used to transmit the synchronization signal by the basestation (block 1250). The method also comprises providing feedback tothe base station, where the feedback comprises information of thetransmit beam for being used by the base station in transmit beammanagement (block 1255). The method can be performed by the electronicdevice 300B, and detailed example operations of the method may refer tothe above description of operations and functions performed by theelectronic device 300B, which are briefly described as follows.

In one embodiment, the transmit beam corresponding to the information oftransmit beam in the feedback is the transmit beam with the highestdegree of reception matching with the terminal device.

In one embodiment, the transmit beam configuration specifies a number ofa plurality of transmit beams that can be used to transmit thesynchronization signal by the base station and a number of times eachtransmit beam can be consecutively used to transmit, the method furthercomprising for each of the number of times of transmissions by the basestation by using each transmit beam consecutively, receive thesynchronization signal by using different receive beams.

In one embodiment, the transmit beam configuration specifies a number oftransmit beams of different levels that can be used to transmit thesynchronization signal by the base station and a number of times eachtransmit beam of different levels can be consecutively used to transmit,and the method further comprising for each of the number of times oftransmissions by the base station by using each transmit beamconsecutively, receive the base station by using different receivebeams.

In one embodiment, the transmit beam configuration further comprisescorrespondence between the transmit beams at the base station side and aplurality of synchronization signal time windows.

In one embodiment, the method further comprises obtaining the transmitbeam configuration from another base station that serves the terminaldevice together with the base station through dual connectivity.

In one embodiment, the other base station is a base station in thewireless communication system, or a base station in a wirelesscommunication system of a previous generation than the wirelesscommunication system.

In one embodiment, the wireless communication system is a 5G system, andthe wireless communication system of the previous generation is an LTEsystem.

In one embodiment, the terminal device or electronic device 300B maycomprise an omnidirectional antenna, the method further comprisingreceiving the synchronization signal without using beamforming to obtainthe transmit beam configuration at the base station side, prior toreceiving the synchronization signal by using the different receivebeams.

In one embodiment, the information of the transmit beam comprises atransmit beam ID, the method further comprising obtaining the transmitbeam ID from the synchronization signal, and the transmit beam ID isindicated by the synchronization signal through one of: thesynchronization signal comprises a synchronization sequence, and thesynchronization sequence per se represents the transmit beam ID; besidesthe synchronization sequence, the synchronization signal comprisesadditional information bits, and the additional information bitsrepresent the transmit beam ID; or time parameters in which thesynchronization signal is located.

In one embodiment, the method further comprises determining theinformation of the transmit beam with the highest degree of matchingbased on the transmit beam configuration and the time parameters of thesynchronization signal transmitted by using the transmit beam withhighest degree of matching.

In one embodiment, the time parameters comprise indices of OFDM symbols,indices of slots in a radio frame and a radio frame number.

In one embodiment, the synchronization signal comprises a primarysynchronization signal PSS and a secondary synchronization signal SSS,or comprises a primary synchronization signal PSS, a secondarysynchronization signal SSS and a tertiary synchronization signal TSS.

In one embodiment, the method further comprises obtaining systeminformation from relative positions of different types ofsynchronization signals in a time or frequency domain, the systeminformation comprising at least one of: a duplex type of the wirelesscommunication system; or a different cyclic prefix length.

Example of Another Electronic Device for Base Station Side

FIG. 13 illustrates an exemplary electronic device for a base stationside in accordance with an embodiment herein, where the base station canbe used in various wireless communication systems. The electronic device1300A shown in FIG. 13 can include various units to implement operationsor functions in accordance with the present disclosure. As shown in FIG.13 , the electronic device 1300A can include, for example, a transmitbeam configuration receiving unit 1360 and a transmit beam configurationproviding unit 1370. In some embodiments, the transmit beamconfiguration receiving unit 1360 can be configured to receive atransmit beam configuration from another base station that transmits asynchronization signal to the terminal device based on the transmit beamconfiguration. The transmit beam configuration providing unit 1370 canbe configured to provide a transmit beam configuration to the terminaldevice for the terminal device to receive signals from base stationbased on the transmit beam configuration.

In one example, the electronic device 1300A can be used with the otherbase station described above in the same wireless communication system,or can be used in a wireless communication system that is the previousgeneration than the other base station described above. For example,electronic device 1300A may be used for an LTE eNB, and the other basestation described above may be a 5G base station, such as a gNB in an NRsystem. According to one implementation, the electronic device 1300A maybe, for example, the first base station in FIG. 9 , and the other basestation may be the second base station in FIG. 9 .

Example Application of Synchronous Signal Beam Scanning

According to one embodiment herein, hierarchical transmit beamformingcan be performed throughout synchronization processes and datacommunication processes. In one example, a first level transmit beamscanning can be performed during the synchronization process and amatching first level transmit beam can be determined. After obtainingthe matching first level transmit beam, the base station can use asecond level transmit beam under the first level transmit beam totransmit a reference signal (such as CSI-RS) in the data communicationprocess, to determine a matching second level transmit beam for datacommunication. FIG. 14 illustrates an example hierarchical transmit beamscanning process flow in accordance with an embodiment herein. As shownin FIG. 14 , at 1461, the base station can transmit synchronizationsignals by a first level transmit beam scanning. At 1462, the terminaldevice receives the synchronization signals, synchronizes to downlinktiming and obtains a first level transmit beam that matches with itself(using receive beamforming or not). Next, at 1463 and 1464, a RA processis performed and the terminal device feeds back the matching first leveltransmit beam to the base station. As mentioned previously, thisfeedback can be made in a variety of appropriate ways. In oneimplementation, the feedback of the matching beam can be performedthrough a RA process. At 1465, the base station records and maintainsthe matching first level transmit beam, such as TX_Bm. Next is the datacommunication process. At 1466, since the base station knows that thefirst level transmit beam TX_Bm matches the terminal device, the CSI-RScan be transmitted by the second level transmit beam under the TX_Bm. At1467, the terminal device receives the CSI-RS and obtains a second leveltransmit beam that matches with itself. At 1468, the terminal devicefeeds back the matching second level transmit beam to the base station.At 1469, the base station records and maintains the matching secondlevel transmit beam, such as TX_Bm,j. Thereafter, the base station canperform data communication with the terminal device using the transmitbeam TX_Bm,j.

The example process of FIG. 14 can save training overhead for beamscanning during the process of data communication, due to thepossibility of utilizing the result of the first level transmit beamscanning in the synchronization process, and performing a second leveltransmit beam scanning during the process of data communicationdirectly, as compared to the conventional method of performing ahierarchical transmit beam scan in a data communication process todetermine a matching second level transmit beam.

A second general aspect in accordance with the present disclosure, whichprimarily discloses a RA process in accordance with embodiments herein,is described below in conjunction with FIGS. 15A-23B. According to someembodiments, a RA signal is transmitted from the terminal device side tothe base station side by beamforming, the base station receives the RAsignal, and obtains information of a transmit beam used by the basestation to transmit the synchronization signal. Thereby the base stationcan know the appropriate transmit beam and receive beam information fora particular terminal device for subsequent communication use. Accordingto one example, in the case the RA is successful, the base station willinform the terminal device of the transmit beam in the uplink thatmatches with the base station. According to some embodiments, theoperations according to the second aspect of the present disclosure canbe performed by electronic devices at the base station side and theterminal device side. The operation according to the second aspect ofthe present disclosure will be described in detail below.

Example of Electronic Device for Terminal Device Side

FIG. 15A illustrates an exemplary electronic device for a terminaldevice side in accordance with an embodiment herein, where the terminaldevice can be used in various wireless communication systems. Theelectronic device 1500A shown in FIG. 15A can include various units toimplement a second general aspect in accordance with the presentdisclosure. As shown in FIG. 15A, in one embodiment, the electronicdevice 1500A can include a PRACH configuration acquisition unit 1505 anda PRACH transmitting unit 1510. According to one implementation, theelectronic device 1500A can be, for example, the terminal device 110 ofFIG. 1 or may be part of the terminal device 110. The various operationsdescribed below in connection with the terminal device can beimplemented by units 1505, 1510 or other units of electronic device1500A.

In some embodiments, the PRACH configuration acquisition unit 1505 canbe configured to obtain RA configuration information. For example, afterobtaining downlink cell synchronization at the terminal device side, theelectronic device 1500A (e.g., unit 1505) can obtain RA configurationinformation at an appropriate location in the downlink frame through thechannel for broadcast. For another example, the terminal device obtainsRA configuration information of the secondary base station through theprimary base station in dual-connectivity. The RA configurationinformation can include a time-frequency domain resource, that is,physical random accesses channel (PRACH), which allows each terminaldevice to transmit a RA preamble thereon. In one embodiment, the RAconfiguration information can further include a correspondence betweenthe receive beams at the base station side and the time domain resources(time windows), as described in detail below.

In some embodiments, the PRACH transmitting unit 1510 can be configuredto transmit a RA preamble based on RA configuration information (e.g.,time-frequency domain resources), to indicate one or more transmit beamsat the base station side in the downlink that matches with one or morereceive beams at the terminal device side. In one embodiment, thematching one or more transmit beams at the base station side aredetermined by the terminal device based on receiving the synchronizationsignal, as described in the first aspect herein. Indicating the matchingtransmit beam by transmission of a RA preamble can be used as a possibleway for the terminal device to feed back the matching transmit beam.

Example of Electronic Device for Base Station Side

FIG. 15B illustrates an exemplary electronic device for a base stationside in accordance with an embodiment herein, where the base station canbe used in various wireless communication systems. The electronic device1500B shown in FIG. 15B can include various units to implement a secondgeneral aspect in accordance with the present disclosure. As shown inFIG. 15B, the electronic device 1500B can include, for example, a PRACHconfiguration providing unit 1515 and a PRACH receiving unit 1520.According to one implementing, the electronic device 1500B may be, forexample, the base station 120 in FIG. 1 or may be part of the basestation 120, or may be a device for controlling a base station (forexample, a base station controller) or a device for a base station, or apart of thereof. The various operations described below in connectionwith the base station can be implemented by units 1515, 1520 or otherunits of electronic device 1500B.

In some embodiments, the PRACH configuration providing unit 1515 can beconfigured to transmit RA configuration information. For example,electronic device 1500B (e.g., unit 1515) can broadcast systeminformation, which can include RA configuration information, atappropriate locations in the downlink frame. The RA configurationinformation can be as described above with reference to unit 1505.

In some embodiments, the PRACH receiving unit 1520 can be configured toreceive a RA preamble transmitted from the terminal device, to obtainone or more transmit beams at the base station side in the downlink thatare paired with one or more receive beams at the terminal device side.In one embodiment, these one or more matching transmit beams at the basestation side are determined by the terminal device based on receivingthe synchronization signal.

Random Access Configuration Information

The RA configuration information can include time-frequency domainresources on which each terminal device is allowed to transmit a RApreamble. In one embodiment, the RA configuration information canfurther include a correspondence between the receive beams at the basestation side and a plurality of RA time windows. The correspondence isgenerally specified by the receive beam configuration at base stationside (as described below), but can be sent to the terminal devicethrough RA configuration information.

In some embodiments, the RA configuration information can also includeother information. For example, the RA configuration information canfurther include indication information of beam symmetry, such as 1 bit.For example, in the case of having beam symmetry, the bit has a value of1; in the case of not having beam symmetry, the bit has a value of 0.According to one example, without beam symmetry, the RA configurationinformation can alternatively or additionally include a receive beamconfiguration at the base station side, thereby enabling the terminaldevice to know the receive beam configuration at the base station side.

In some embodiments, above other information and the correspondencebetween the receive beams at the base station side and the plurality ofRA time windows can also be sent to the terminal device in other ways,for example, by way of dual connectivity.

Random Access Time Window and Random Access Preamble

1n general, RA preambles can be transmitted in specific time windows inuplink frames, and these time windows can be arranged with a certaintime period or time pattern. These time windows can correspond to aparticular transceiving occasion of the RA signal. In an embodimentherein, since the base station side uses beamforming to receive the RApreambles, more RA time windows are needed for receive beam scanning,ie: 1) receptions using multiple different beams, and 2) repetitivereceptions using a single beam. In some embodiments, consecutive RA timewindows can be arranged within one frame or across multiple frames. Onecorresponding example can be seen in FIG. 16 . As shown in FIG. 16 , aplurality of RA time windows 1650 to 1661 can be consecutive in the timedomain to form a larger RA time window 1680. The RA time window 1650 to1661 can also be referred to as basic RA resources. Taking the framestructure in the LTE system as an example, the basic RA resources cancorrespond to several (for example, six) resource blocks in the centerof the frequency band, and its length may be 1 ms, 2 ms, or 3 msaccording to the system configuration. The larger RA time window 1680can be arranged with a certain period. One purpose of forming a RA timewindow 1680 is to enable the base station to finish a complete receivebeam scanning within the larger time window.

In some embodiments, the RA time windows can be designated to correspondto particular time parameters of the uplink frame. For example, a framenumber, a subframe number, a slot index, and/or a symbol index of a RAtime window can be specified. In some embodiments, the terminal devicecan identify a RA time window based on the time parameters such that theRA preamble can be selectively transmitted in the RA time window.

As shown in FIG. 16 , a RA preamble (e.g., RA preamble 1670) can betransmitted in any of the RA time windows 1650 to 1661. In someembodiments, the RA preamble can include a cyclic prefix and a RAsequence, which RA sequence can be, for example, a Zadoff-Chu sequence.In some embodiments, the RA preamble can also include additionalinformation bits. According to an embodiment herein, the RA preamble canbe used to indicate one or more transmit beams at the base station sidethat match with the terminal device. For example, a RA sequence oradditional information bits can be used to indicate the matchingtransmit beams at the base station side described above.

Receive Beam Configuration at Base Station Side

In receive beamforming, a repetition pattern of a plurality of receivebeams at the base station side can be represented by a receive beamconfiguration. In some embodiments, on one hand, the base station canreceive a RA preamble from each terminal device based on the receivebeam configuration; on the other hand, the terminal device may need totransmit RA preambles based on the receive beam configuration, forexample, when the terminal device transmits by using transmitbeamforming. In general, to represent a repetition pattern of receivebeams, the receive beam configuration can include or indicate at leasttwo aspects of information, i.e., the number of receive beams and thenumber of times each receive beam is repetitively used to receive (e.g.,a RA preamble).

In some embodiments, the receive beam configuration can specify thenumber of receive beams that can be used by the base station to receivethe RA preamble and the number of times each receive beam isconsecutively used to receive. FIG. 17A illustrates an exemplary receivebeam configuration at the base station side in accordance with anembodiment herein. As shown in FIG. 17A, the receive beam configuration1700A designates that the base station side has four receive beams RX_B1to RX_B4 for receiving the RA preamble, and can consecutively use eachreceive beam three times for the reception. Similar to the above exampleof the transmit beam configuration, the receive beam configuration canalso be represented in N (beams)×M (times). For example, the receivebeam configuration 1700A can be referred to as 4×3 configuration forshort. This receive beam configuration is only an example. In variousembodiments, the number of receive beams can be any number, and thenumber of repetitions can be any number of times.

In a corresponding embodiment, the electronic device 1500B can beconfigured to receive RA preambles using each of a plurality of (e.g.,four) receive beams based on a receive beam configuration, and toconsecutively use each receive beam to perform this reception for aspecified number of times (e.g., 3 times). If the terminal device doesnot use transmit beam scanning to transmit the RA preamble, theelectronic device 1500A can only need to use the full-width beam toperform the transmission to the base station; if the terminal deviceneeds to use transmit beamforming, the electronic device 1500A can usedifferent transmit beam to transmit the RA preambles for the basestation to receive based on the receive beam configuration.

In some embodiments, the receive beam configuration can specify thenumber of different levels of receive beams that the base station canuse to receive the RA preambles and the number of times each receivebeam of different levels is consecutively used to received. FIG. 17Billustrates an exemplary receive beam configuration in the case of ahierarchical receive beam at the base station side in accordance with anembodiment herein. It is assumed that there are four first level receivebeams at the base station side, and each first level receive beam hastwo second level receive beams. The first level of receive beamconfiguration can be, for example, as shown in FIG. 17A, and the secondlevel of receive beam configuration can be, for example, as shown inFIG. 17B. The second level of receive beam configuration 1700B isassigned with eight second level receive beams RX_B1, 1 to RX_B4, 2 forreceiving RA preambles, and each second level receive beam can be usedconsecutively for 3 times for reception. In some cases, the hierarchicalreceive beam configuration can also be represented in the form of N×M.For example, the first level receive beam configuration of FIG. 17B canbe represented as 4×3 configuration, and the second level receive beamconfiguration can be represented as 2×3 configuration (where “2” secondlevel receive beams correspond to a single first level transmit beam) or8×3 configuration (where “8” second level receive beams correspond tothe whole first level transmit beam).

In a corresponding embodiment, the electronic device 1500B can beconfigured to receive RA preambles using each of the different levels ofreceive beams and consecutively use each receive beams for the specifiednumber of times for the reception. If the terminal device does not usebeamforming to transmit the RA preamble, the electronic device 1500A canonly need to use the full-width beam to perform the transmission to thebase station; if the terminal device needs to use transmit beamforming,the electronic device 1500A can be configured to transmit the RApreambles using different levels of transmit beams for the base stationto receive based on the receive beam configuration.

In the above embodiments, in the case where the terminal device isrequired for the transmit beam scanning, the electronic device 1500Aneeds to know or be able to know the receive beam configuration at thebase station side, thereby determining its own transmit beamarrangement, as described below with reference to FIG. 19A to 20B.

In some embodiments, the receive beam configuration can also indicate acorrespondence between the receive beams at the base station side and aplurality of RA time windows. In one example, the receive beamconfiguration can indicate a correspondence between each reception ofeach receive beam and a plurality of RA time windows (or referred to asa full correspondence). In another example, the receive beamconfiguration can indicate a correspondence between a reception of acertain receive beam and a plurality of RA time windows (or referred toas a partial correspondence). For example, it may be specified that thefirst reception using the first receive beam RX_B1 corresponds to thefirst RA time window. The base station side or the terminal device sidecan determine a full correspondence based on a partial correspondence inconnection with the repetition pattern of receive beams. In such anembodiment, the electronic device 1500B can perform the first receptionand subsequent reception of the RA preambles using the receive beamRX_B1 based on the above-described correspondence. Accordingly, theelectronic device 1500A can transmit a RA preamble based on thecorrespondence.

FIG. 18 illustrates a correspondence between receive beams at the basestation side and RA time windows in accordance with an embodimentherein. FIG. 18 illustrates an exemplary correspondence in a 4×3 receivebeam configuration. As shown in FIG. 18 , based on the correspondencethat the first reception using the first receive beam RX_B1 correspondsto the first RA time window, in the first set of three RA time windows,the RA preambles are received each using the first receive beams (e.g.,RX_B1). In the second set of three RA time windows, they are receivedeach using the second receive beam. Next, in the third, the fourth setsof RA time windows, they are received each using the third and fourthreceive beams, respectively. It is to be noted that FIG. 18 onlyillustrates one cycle of an exemplary beam configuration, the abovearrangement may be repeated at a later time to receive RA preambles.

In some embodiments, in the hierarchical beamforming, a correspondencebetween receive beams at the base station side and a plurality of RAtime windows can include a correspondence between a plurality of levelsof receive beams at the base station side and a plurality of RA timewindows.

Transmit Beam Arrangement on Terminal Device Side

In the case where transmit and receive beams in the uplink and downlinkhave symmetry, if a terminal device has obtained a transmit beamconfiguration at a base station side before transmitting a RA preamble(for example, during the reception of synchronization signal), theterminal device can determine a receive beam configuration at the basestation side according to the beam symmetry. Then, if the terminaldevice has determined its own receive beam arrangement as that in FIG. 8, its transmit beam configuration can be determined directly based onthe correspondence between receive and transmit beams on either side(transmitting or receiving side) under beam symmetry. That is, theterminal device only needs to be on the basis of indication of beamsymmetry to determine its own transmit beam configuration.

Without the beam symmetry, if a terminal device needs to use transmitbeamforming to transmit a RA preamble, it can determine its own transmitbeam arrangement based on the receive beam configuration at the basestation side. Then, the base station can notify the terminal device ofits receive beam configuration. For example, the receive beamconfiguration can be notified via the dual connectivity shown in FIG. 9. After the dual connectivity is established with the two base stationsvia the process of FIG. 9 and the base station serves as the secondarynode and the other base station serves as the primary node, the terminaldevice can obtain the receive beam configuration of the base stationwhich serves as the secondary node via the primary node. As anotherexample, the base station can inform its receive beam configurationthrough system information. After obtaining the receive beamconfiguration at the base station side, the terminal device candetermine its own transmit beam arrangement, as described in detailbelow.

The terminal device may transmit a RA preamble with or without transmitbeamforming. FIG. 19A illustrates an exemplary transmit beam arrangementof a terminal device under a 4×3 receive beam configurations at the basestation side. The transmit beam arrangements 1 and 2 in FIG. 19Acorrespond to the case where the terminal device does not use transmitbeamforming to transmit a RA preamble. Then, the electronic device 1500Acan generally use transmit beam arrangement 1, i.e., use a full-widthtransmit beam (e.g., TX_B1) for each transmission of each transmit beam.The advantage of the transmit beam arrangement 1 is, for example, thatthe RA preamble can be transmitted multiple times to achieve a diversitygain. The electronic device 1500A, in the case of knowing the receivebeam configuration of the base station side, can also use the transmitbeam arrangement 2, i.e., for multiple receptions of each receive beam,only to transmit once by using a full-width transmit beam (eg TX_B1).The advantage of the transmit beam arrangement 2 is that thetransmission resources (e.g., power, etc.) of the terminal device can besaved and the occupation of RA resources can be reduced, thus avoidingcollisions between terminal devices.

The transmit beam arrangements 3 and 4 in FIG. 19A correspond to thecase where a terminal device transmits RA preambles using 2 or 3different transmit beams, respectively. Then, for multiple receptions ofeach receive beam, the electronic device 1500A needs to transmit usingdifferent transmit beams. In the receive beam arrangement 3 or 4, sincethe electronic device 1500A knows that each receive beam is repeated 3times at the base station side, it is possible to arrange its owntransmit beam in these 3 repetitions, so that each transmit beam is usedat least once, thereby realizing the purpose of beam scanning. FIG. 19Aillustrates only one cycle of transmission of different transmit beams,which can be followed by the next cycle.

Similar to the case of the aforementioned receive beam arrangement at aterminal device side, in light of the teachings herein, those skilled inthe art can conceive various variations of receive beam configurationsto implement beam scanning, all of which fall within the scope of thepresent disclosure.

It should be understood that in the hierarchical receive beamconfiguration at the base station side, FIG. 19A can be considered tohave shown the first level receive beams and various transmit beamarrangements at the corresponding terminal device side. The first levelbeams can be followed by the second level the beams. FIG. 19Billustrates a second level of receive beam configuration and anexemplary transmit beam arrangement of a terminal device. The firstlevel of the hierarchical receive beam configuration is 4×3configuration, and the second level of the configuration is 2×3configuration (where each first level receive beam corresponds to twosecond level receive beams) (For simplicity, only the second level beamscorresponding to the first two first level beams are shown). In oneexample, after receptions using the first level receive beams as that inFIG. 19A, the receptions can then be done using the second level receivebeams, as shown in the receive beam configuration in FIG. 19B. In FIG.19B, each of the second level receive beams corresponding to each of thefirst level receive beams is successively repeated up to the number oftimes indicated in the receive beam configuration. For example, thesecond level receive beam RX_B1,1 corresponding to the first levelreceive beam RX_B1, is first repeated 3 times, and then RX_B1, 2 is alsorepeated 3 times, thereby completing the scanning of the second leveltransmit beams corresponding to the first level receive beam RX_B1.Next, scanning of the second level receive beams corresponding to thenext second level receive beams is sequentially performed.

Similar to that described in FIG. 19A, in FIG. 19B, the transmit beamarrangements 1 and 2 correspond to the case where the terminal devicedoes not use transmit beamforming. Thus, the electronic device 1500A canuse the transmit beam arrangement 1, i.e., use a full-width transmitbeam (e.g., TX_B1) to transmit a RA preamble. As mentioned previously,the transmit beam arrangement 1 can achieve a diversity gain. In thecase where the electronic device 1500A knows a receive beamconfiguration at a base station, the electronic device 1500A can alsouse the transmit beam arrangement 2, i.e., for multiple receptions ofeach receive beam, only to transmit once using a full-width transmitbeam (e.g., TX_B1). The advantage of the transmit beam arrangement 2 isthat the transmitting resources (e.g., power, etc.) of the terminaldevice can be saved and the occupation of RA resources can be reduced,thus avoiding collisions between terminal devices.

The transmit beam arrangements 3 and 4 in FIG. 19B correspond to thecase where a terminal device transmits RA preambles using 2 or 3different transmit beams, respectively. Thus, for multiple receptions ofeach second level the receive beams, the electronic device 1500A needsto transmit using different transmit beams. To this end, the electronicdevice 1500A needs to know the receive beam configuration of the basestation to arrange the corresponding transmit beams. In the transmitbeam arrangement 3 or 4, since the electronic device 1500A knows thateach second level receive beam is repeated 3 times, it is possible toarrange its own transmit beams in these 3 repetitions, so that eachtransmit beam is used at least once, thereby realizing the purpose ofbeam scanning. FIG. 19B illustrates one cycle of different second levelbeam transmissions. In the case of a hierarchical beam scan, aftercompleting one cycle of the second level beam scan, a first level beamscan and a second level beam scan of the next cycle can be performed.Those of ordinary skill in the art, in the light the teachings herein,can conceive various variations of transmit beam configurations toimplement beam scanning, all of which are within the scope of thepresent disclosure.

Feedback of Matching Transmit Beam at Base Station Side

An example operation of a terminal device feeding back a matchingtransmit beam at a base station side to the base station in accordancewith an embodiment herein is described below. In some embodiments, oneor more transmit beams at the base station side paired with one or morereceive beams at the terminal device side are determined by the terminaldevice based on receiving synchronization signals. In some embodiments,a RA preamble transmitted by the terminal device can indicate one ormore transmit beams at the base station side in the downlink paired withone or more receive beams at the terminal device side.

In one embodiment, transmit beam IDs of one or more transmit beams atthe base station side that are paired with receive beams at a terminaldevice side are indicated by a RA preamble. For example, the RA preamblecan include a preamble sequence (e.g., a Zadoff-Chu sequence), whichpreamble sequence per se can represent a transmit beam ID. This issimilar to the example of FIG. 11A in that the preamble sequences can bedivided into multiple groups, and all preamble sequences in a same groupcan represent a same transmit beam. For a 4×3 transmit beamconfiguration, these preamble sequences can be divided (e.g., equallydivided) into 4 groups, and the sequences in each group can representone of the 4 transmit beams. For example, any of the first group ofsequences (1st to N/4th sequences) can represent the transmit beam ID 1.The electronic device 1500A can transmit a preamble sequencecorresponding to the transmit beam with ID 1 when feeding back thistransmit beam ID 1. After determining that one of the first group ofsequences is received, the electronic device 1500B can determine that IDof the matching transmit beam is the transmit beam ID 1. Of course, insuch an embodiment, the base station and the terminal device are alsorequired to agree upon the correspondence between each group of preamblesequences and the transmit beams (for example, the terminal device isnotified by the base station with any signaling).

For another example, in addition to the preamble sequences, the RApreamble can further include additional information bits, which canrepresent the transmit beam ID. In one example, a single transmission ofa RA preamble can indicate a single transmit beam ID. Referring to theexample of FIG. 11B, for the 4×3 transmit beam configuration, additionalbits 00, 01, 10, 11 can be designated to represent one of the 4 transmitbeams, respectively. For example, the additional information bits 00 canrepresent the transmit beam ID 1. The electronic device 1500A cantransmit the additional information bits 00 when feeding back thetransmit beam ID 1. After determining that the additional bits 00 isreceived, the electronic device 1500B can determine that the matchingtransmit beam ID is the transmit beam ID 1. In such an embodiment,similarly, the base station and the terminal device are required toagree upon the correspondence between the additional bits and transmitbeams. In one example, a single transmission of the RA preamble canindicate multiple transmit beam IDs. The number of additionalinformation bits described above can be increased, for example, in theexample of FIG. 11B, 2 transmit beam IDs can be indicated using 4 bits.

According to the exemplary arrangements 1 to 4 of the terminal devicetransmit beams shown in FIGS. 19A and 19B, for each receive beam (e.g.,RX_B1 to RX_B4 and each fine beams) at the base station side, terminaldevice can transmit RA preambles. This approach is applicable to both inuplink and downlink with or without beam symmetry. In some embodiments,for example, where the terminal device knows the matching receive beamat the base station side, the terminal device can just transmit a RApreamble for the matching receive beam, as described below withreference to FIGS. 20A and 20B.

FIGS. 20A and 20B illustrate an example of transmitting RA preamblesbased on a transmit beam arrangement at a terminal device side. Thetransmit beam configurations at the terminal device side in FIGS. 20Aand 20B are the same as those in FIGS. 19A and 19B, with the exceptionthat the RA preambles are only transmitted for a specific receive beamat the base station side. Moreover, these transmissions can be madeusing a specific transmit beam, as indicated by the shadow in thefigure. This approach can be applied to the case where there is beamsymmetry in the uplink and/or downlink. In this case, if the terminaldevice knows the matching transmit receive beams pair in the downlink(e.g., determined by the reception of the synchronization signal), thematching transmit receive beams pair in the uplink can be determined, tofacilitate transmission of the RA preamble.

For example, in FIG. 20A, for the first level beam scanning, assumingthat the terminal device determines the transmit beam TX_B1 at the basestation side matches with the receive beam RX_B2 at the terminal deviceside in downlink, then it can be determined that the receive beam at thebase station side matching with the terminal device in uplink is RX_B1,which matches with the transmit beam TX_B2 at the terminal device side.Accordingly, the terminal device can transmit the RA preamble (forexample, using the transmit beams TX_B1 to TX_B3) only in the RA timewindows corresponding to the receive beam RX_B1. Further, the terminaldevice can transmit the RA preamble using the matching transmit beamTX_B2 only in the RA time windows corresponding to the receive beamRX_B1 (shown by the shadow in the figure). For transmit beamconfigurations 1 and 2, since the full-wave transmission is used by theterminal device, the RA preamble can be transmitted using the full-wavetransmission only in the RA time windows corresponding to the receivebeam RX_B1.

FIG. 20B illustrates an example of a second level beam scanningcorresponding to FIG. 20A. In the second level beam scanning, assumingthat the terminal device determines that transmit beams TX_B1, 2 at thebase station side matches with the receive beam RX_B2 at the terminaldevice side in downlink, then it can be determined that the receive beamat the base station side matching with the terminal device in uplink isRX_B1, 2, which matches with the transmit beam TX_B2 at the terminaldevice side. Accordingly, the terminal device can transmit the RApreamble (for example using the transmit beams TX_B1 to TX_B3) only inthe RA time windows corresponding to the receive beam RX_B1, 2. Further,the terminal device can transmit the RA preamble using the matchingtransmit beam TX_B2 only in the RA time windows corresponding to thereceive beam RX_B1, 2 (shown by the shadow in the figure). For transmitbeam configurations 1 and 2, since the full-wave transmission is used bythe terminal device, the RA preamble can be transmitted using thefull-wave transmission only in the RA time windows corresponding to thereceive beam RX_B1, 2.

In the above example, when the RA preamble is transmitted in aparticular RA time window, the particular RA time window per se canindicate transmit beam ID of one or more transmit beams at the basestation side paired with one or more receive beams at the terminaldevice side in downlink. FIG. 21A illustrates an example method in whicha terminal device transmits a RA preamble in accordance with anembodiment herein. At 2105, in the case that the matching transmitbeam(s) at the base station side and receive beam(s) at the terminaldevice side in downlink are known, the terminal device can determine,based on the beam symmetry, the matching receive beam(s) at the basestation side and transmit beam(s) at the terminal device side in uplink.At 2110, the terminal device can determine, based on the correspondencebetween receive beam(s) at the base station side and a plurality of RAtime windows, from the plurality of RA time windows, one or more RA timewindows corresponding to receiving beam(s) at the base station side. At2115, the terminal device can transmit the RA preambles with one or moretransmit beams at the terminal device side in at least a part of the oneor more RA time windows.

FIG. 21B illustrates an example method in which a base station receivesRA preambles in accordance with an embodiment herein. At 2150, the basestation can receive the RA preambles with the receive beam at the basestation side based on the correspondence between receive beam(s) at thebase station side and a plurality of RA time windows. It can beunderstood that the base station should receive the corresponding RApreamble in the RA time window corresponding to the receive beam at thebase station side determined at step 2110. At 2155, the base station candetermine the receive beam that receives the RA preamble based on thecorrespondence between the receive beams at the base station side andthe RA time windows. At 2160, the base station can determine, based onbeam symmetry, the transmit beam corresponding to the receive beam atthe base station side, i.e., the transmit beam in downlink that matcheswith the terminal device.

In the above method example, the RA time window per se can indicate atransmit beam ID. Thus, ID of the same matching transmit beam can beindicated by a synchronization sequence or additional information bitsto increase the robustness of transmit beam ID detection. Alternatively,ID of another matching transmit beam can be indicated by thesynchronization sequence or additional information bits such that asingle transmission of the RA preamble can indicate multiple transmitbeam IDs.

According to the foregoing embodiment, a single transmission of the RApreamble can indicate multiple transmit beam IDs. Alternatively oradditionally, in some embodiments, one or more transmit beams at thebase station side in downlink that are paired with one or more receivebeams at the terminal device side can be indicated by an uplink messagesubsequent to the RA preamble. For example, the matching transmit beamat the base station side can be indicated by the MSG-3 message in FIG. 1.

Retransmission of Random Access Preamble

According to some embodiments, in the case where a RA preamble needs tobe retransmitted, a terminal device can preferably use a transmit beamthat is most relevant to direction of the previous transmit beam at theterminal device side for the retransmission, wherein the directionrelevance includes transmission directions are adjacent or at leastpartially overlapping.

After transmitting a RA preamble for a first time, the terminal devicewaits for a RA response (RAR) transmitted by the base station within acertain time windows. If the RAR is received, the terminal devicedetermines that the RA preamble is successfully transmitted. If theterminal device fails to receive the RAR within the RAR waiting timewindows, as shown in FIG. 22 , the terminal device needs to retransmitthe RA preamble. In some embodiments, during retransmission, in order toavoid waste of resources caused by global beam scanning, the terminaldevice can select a transmit beam for retransmission around the transmitbeams used for transmitting the RA preamble for the first time. Thetransmit beam around can be the transmit beams most relevant to thedirection of the transmit beam used at the first time and thus may bethe beam that best matches with the base station. That is, it can beconsidered that the beams around the transmit beam used at the firsttime can form a Candidate Beam Set, as shown in FIG. 22 . During theretransmission process of RA preamble, the transmission power can begradually increased by a step size until the upper limit of thetransmission power of the terminal device. If the terminal device stillfails to receive the RAR after retransmitting the RA preamble, the rangeof the beam scanning can be expanded for transmission. Thereafter, theprocess is repeated until the terminal device receives the RAR.

According to an embodiment herein, after the range of the beam scanningis expanded for transmitting the RA preamble, the base station cannotify the terminal device of a transmit beam matching with the basestation in uplink in the RAR message.

Exemplary Method

FIG. 23A illustrates an example method for communication in accordancewith an embodiment herein. As shown in FIG. 23A, the method 2300A caninclude obtaining information of a RA configuration (block 2305). Themethod also includes transmitting a RA preamble based on the informationof the RA configuration, to indicate one or more transmit beams at thebase station side that paired with one or more receive beams at theterminal device side in downlink (block 2310). The method can beperformed by electronic device 1500A, and detailed example operations ofthe method may refer to the above description of the operations andfunctions performed by the electronic device 1500A, which are brieflydescribed as follows.

In one embodiment, one or more transmit beams at the base station sidepaired with one or more receive beams at the terminal device side aredetermined by the terminal device based on receiving the synchronizationsignal.

In one embodiment, the RA preamble indicates identification informationof one or more transmit beams at the base station side paired with oneor more receive beams at the terminal device side, such as a transmitbeam ID.

In one embodiment, the RA preamble indicates transmit beam IDs of one ormore transmit beams at the base station side paired with one or morereceive beams at the terminal device side by at least one of: the RApreamble includes a preamble sequence, the preamble sequence per serepresenting a transmit beam ID; or the RA preamble further includesadditional information bits, the additional information bitsrepresenting the transmit beam ID.

In one embodiment, a single transmission of the RA preamble can indicatea single transmit beam ID or multiple transmit beam IDs.

In one embodiment, the RA configuration information further includescorrespondence between beams at the base station side and a plurality ofRA occasions, and the method further includes: repetitively transmittingthe RA preamble with different transmit beams at the terminal side basedon the correspondence; or repetitively transmitting the RA preamble withtransmit beams corresponding to one or more receive beams at theterminal device side based on the correspondence.

In one embodiment, the method further comprises transmitting a RApreamble in a particular RA occasion, the particular RA occasionindicating transmit beam IDs of one or more transmit beams at the basestation side paired with one or more receive beams at the terminaldevice side in downlink.

In one embodiment, the RA configuration information further includescorrespondence between beams at the base station side and a plurality ofRA occasions, where there is beam symmetry in uplink and/or downlinkbetween the base station and the terminal device, the method furtherincludes transmitting a RA preamble by: determining the one or morematching receive beams at the base station side and one or more transmitbeams at the terminal device side in uplink based on the beam symmetry;determining one or more RA occasions corresponding to one or more beamsat the base station side from the plurality of RA occasions based on thecorrespondence; and transmitting the RA preamble with one or moretransmit beams of the terminal device side in at least a part of the oneor more RA occasions.

In one embodiment, the correspondence between beams at the base stationside and a plurality of RA occasions includes correspondence betweenmultiple levels of beams at the base station side and multiple RAoccasions.

In one embodiment, the method further comprises indicating one or moretransmit beams at the base station side paired with one or more receivebeams at the terminal device side in downlink by an uplink messagesubsequent to the RA preamble.

In one embodiment, the method further comprises retransmitting bypreferably using a transmit beam that is most relevant to direction ofthe previous transmit beam at the terminal device side in the case wherea RA preamble needs to be retransmitted, wherein the direction relevanceincludes transmission directions are adjacent or at least partiallyoverlapping.

In one embodiment, the synchronization signal corresponds to a SS blockcomprising a PSS, a SSS, and a PBCH, the method further comprisesreceiving a plurality of SS blocks transmitted by different transmitbeams at the base station side within a shorter period in time domain,and using transmit beams at the base station side corresponding to SSblocks in which signal reception quality satisfies a predeterminedcondition as transmit beams at the base station side paired with theterminal device.

In one embodiment, the method further comprises determining, based onthe reference signal sequence per se in the SS block that satisfies thepredetermined condition, a transmit beam used to transmit the SS blockby the base station.

In one embodiment, the method further comprises determining, based onthe additional information bits in the SS block that satisfies thepredetermined condition, a transmit beam used to transmit the SS blockby the base station.

In one embodiment, the method further comprises receiving radio resourcecontrol signaling and obtaining the RA configuration informationtherefrom.

In one embodiment, an electronic device performing the method canoperate as a terminal device, which can include one or more radiofrequency links, each radio frequency link being coupled to a pluralityof antennas and their phase shifters. The terminal device (e.g., itsprocessing circuitry) can configure the phase shifters of the pluralityof antennas based on beam directions that match with the beams at thebase station side, to cause the plurality of antennas transmit the RApreamble to the base station by beamforming. In one embodiment, thewireless communication system is a fifth generation New Radiocommunication system and the base station is a gNB.

FIG. 23B illustrates another example method for communication inaccordance with an embodiment herein. As shown in FIG. 23B, the method2300B can include transmitting information of the RA configuration(block 2350). The method also includes receiving a RA preambletransmitted from the terminal device, to obtain one or more transmitbeams at the base station side that are paired with one or more receivebeams at the terminal device side in downlink (block 2355). The methodcan be performed by electronic device 1500B, and detailed exampleoperations of the method may refer to the above description ofoperations and functions performed by electronic device 1500B, which arebriefly described as follows.

In one embodiment, one or more transmit beams at the base station sidepaired with one or more receive beams at the terminal device side aredetermined by the terminal device based on receiving the synchronizationsignal.

In one embodiment, the RA preamble indicates identification informationof one or more transmit beams at the base station side paired with oneor more receive beams at the terminal device side, such as a transmitbeam ID.

In one embodiment, the RA preamble indicates transmit beam IDs of one ormore transmit beams at the base station side paired with one or morereceive beams at the terminal device side by at least one of: the RApreamble includes a preamble sequence, the preamble sequence per serepresenting a transmit beam ID; or the RA preamble further includesadditional information bits, the additional information bitsrepresenting the transmit beam ID.

In one embodiment, a single transmission of the RA preamble can indicatea single transmit beam ID or multiple transmit beam IDs.

In one embodiment, the RA configuration information further includescorrespondence between beams at the base station side and a plurality ofRA occasions, and the method further includes receiving the RA preamblewith beams at the base station side based on the correspondence.

In one embodiment, the method further comprises receiving a RA preamblein a particular RA occasion, the particular RA occasion indicatingtransmit beam IDs of one or more transmit beams at the base station sidepaired with one or more receive beams at the terminal device side indownlink.

In one embodiment, the RA configuration information further includescorrespondence between beams at the base station side and a plurality ofRA occasions, where there is beam symmetry in uplink and/or downlinkbetween the base station and the terminal device, the method furtherincludes receiving a RA preamble by: receiving the RA preamble with areceive beam at the base station side based on the correspondence;determining a receive beam that receives the RA preamble; anddetermining a transmit beam corresponding to the receive beam at thebase station side based on the beam symmetry.

In one embodiment, the correspondence between beams at the base stationside and a plurality of RA occasions includes correspondence betweenmultiple levels of beams at the base station side and multiple RAoccasions.

In one embodiment, the method further comprises obtaining one or moretransmit beams at the base station side paired with one or more receivebeams at the terminal device side in downlink from an uplink messagesubsequent to the RA preamble.

In one embodiment, the synchronization signal corresponds to a SS blockcomprising a PSS, a SSS, and a PBCH, the method further comprisestransmitting a plurality of SS blocks by different transmit beams at thebase station side within a shorter period in time domain.

In one embodiment, the SS block indicates, by the reference signalsequence per se in the SS block, information of the transmit beam usedto transmit the SS block by the base station.

In one embodiment, the SS block further includes additional informationbits through which to indicate the information of transmit beams used totransmit the SS block by the base station.

In one embodiment, the method further comprises transmitting radioresource control signaling to transmit the RA configuration informationto the terminal device. In one embodiment, the wireless communicationsystem is a fifth generation New Radio communication system and the basestation is a gNB.

In some embodiments, the electronic devices 300A, 300B, 1300A, 1500A,and 1500B, etc., can be implemented at the chip level, or can beimplemented at the device level by including other external components.For example, each electronic device can operate as a communicationdevice operating as a unity machine.

It should be noted that the above-mentioned respective units are onlylogical modules divided according to the specific functions theyimplement, and are not intended to limit specific implementations. Forexample, they can be implemented in software, hardware or a combinationof software and hardware. In actual implementation, each of the aboveunits can be implemented as separate physical entities, or can beimplemented by as a single entity (e.g., a processor (CPU or DSP, etc.),an integrated circuit, etc.). Processing circuitry can refer to variousimplementations of digital circuitry, analog circuitry, or mixed signal(combination of analog and digital) circuitry that perform functions ina computing system. Processing circuitry can include, for example,circuitry such as an integrated circuit (IC), an application specificintegrated circuit (ASIC), a portion or circuit of a separate processorcore, an entire processor core, a separate processor, a programmablehardware device such as a field programmable gate array (FPGA), and/orsystems including multiple processors.

Various exemplary electronic devices and methods in accordance with thepresent disclosure are described above. It should be understood that theoperations or functions of these electronic devices can be combined witheach other to achieve more or less operations or functions than thosedescribed. In one embodiment, one electronic device can implement all ofthe operations or functions of electronic devices 300A, 1300A, and1500B, or one electronic device can implement all of the operations orfunctions of electronic devices 300B and 1500A. The operational steps ofthe various methods can also be combined with one another in anysuitable order to similarly achieve more or less operations than thosedescribed.

For example, according to still another aspect of the presentdisclosure, an electronic device for a terminal device side in awireless communication system can include processing circuitryconfigured to: receive, from a base station in the wirelesscommunication system, a plurality of synchronization signal blocksincluding, respectively, a PSS, a SSS, and a PBCH, for downlinksynchronization, wherein the plurality of synchronization signal blocksare transmitted by different transmit beams at the base station side,and each synchronization signal block can indicate information of atransmit beam used to transmit the synchronization signal block by thebase station; determining a synchronization signal block that matcheswith the terminal device based on reception quality; and transmitting aRA preamble to the base station to perform a RA process, wherein the RApreamble can indicate information of the transmit beam used to transmitthe matching synchronization signal block by the base station, for beingused by the base station in beam management.

In one embodiment, the synchronization signal block indicates, by areference signal sequence per se in the synchronization signal block,information of the transmit beam used to transmit the synchronizationsignal block by the base station.

In one embodiment, the synchronization signal block further comprisesadditional information bits by which to indicate information of thetransmit beam used to transmit the synchronization signal block by thebase station.

In one embodiment, the preamble sequence of the RA preamble indicatesinformation of the transmit beam used to transmit the matchingsynchronization block by the base station.

In one embodiment, a plurality of preamble sequences are used toindicate information of the transmit beam for a same synchronizationsignal block, and the electronic device determines correspondencebetween a plurality of preamble sequences and the transmit beam for thesynchronization signal block from a signaling from the base station.

In one embodiment, the processing circuitry is further configured to:receive, from the base station, a radio resource control signalingincluding RA configuration information, wherein the RA configurationinformation comprises correspondence between beams at the base stationside and a plurality of RA occasions; and select a specific RA occasionto transmit a RA preamble according to the RA configuration information,to indicate information of the transmit beam used to transmit thematching synchronization signal block by the base station.

In one embodiment, the processing circuitry is further configured toreceive a CSI-RS beam transmitted by the base station in a transmit beamdirection corresponding to the matching synchronization signal block,and feedback information of the CSI-RS beam matching with the terminaldevice to the base station.

In one embodiment, the processing circuitry is further configured toreceive the plurality of synchronization signal blocks by using aplurality of receive beams and determine the matching receive beam ofthe terminal device according to reception quality.

In one embodiment, the wireless communication system has beam symmetry,and the processing circuitry is further configured to transmit to thebase station the RA preamble by using the transmit beam at the terminaldevice side corresponding to the matching receive beam of the terminaldevice.

In one embodiment, the processing circuitry is further configured to, ina case where a RA response by the base station is not received within apredetermined time period after transmitting the RA preamble, retransmitthe RA preamble by using a transmit beam around the transmit beam at theterminal device side.

In one embodiment, the wireless communication system is a 5G NR system,the base station is a gNB, and the terminal device comprises a pluralityof antennas for transmitting signals by beamforming.

For example, according to still another aspect of the presentdisclosure, a method for a terminal device side in a wirelesscommunication system comprises: receiving, from a base station in thewireless communication system, a plurality of Synchronization Signalblocks including, respectively, a PSS, a SSS, and a PBCH, for downlinksynchronization, wherein the plurality of synchronization signal blocksare transmitted by different transmit beams at the base station side,and each synchronization signal block can indicate information of thetransmit beam used to transmit the synchronization signal block by thebase station; determining a synchronization signal block that matcheswith the terminal device based on reception quality; and transmitting aRA preamble to the base station to perform a RA process, wherein the RApreamble can indicate information of the transmit beam used to transmitthe matching synchronization signal block by the base station, for beingused by the base station in beam management.

In one embodiment, the synchronization signal block indicates, by areference signal sequence per se in the synchronization signal block,information of the transmit beam used to transmit the synchronizationsignal block by the base station.

In one embodiment, the synchronization signal block further comprisesadditional information bits by which to indicate information of thetransmit beam used to transmit the synchronization signal block by thebase station.

In one embodiment, the preamble sequence of the RA preamble indicatesinformation of the transmit beam used to transmit the matchingsynchronization signal block by the base station.

In one embodiment, a plurality of preamble sequences are used toindicate information of the transmit beam for a same synchronizationsignal block, the method further comprising determining correspondencebetween a plurality of preamble sequences and the transmit beam for thesynchronization signal block from a signaling from the base station.

In one embodiment, the method further comprises: receiving, from thebase station, a radio resource control signaling including RAconfiguration information, wherein the RA configuration informationcomprises correspondence between beams at base station side and aplurality of RA occasions; and selecting a specific RA occasion totransmit a RA preamble according to the RA configuration information, toindicate information of the transmit beam for the matchingsynchronization signal block to the base station.

In one embodiment, the method further comprises receiving a CSI-RS beamtransmitted by the base station in a transmit beam directioncorresponding to the matching synchronization signal block, and feedingback information of the CSI-RS beam matching with the terminal device tothe base station.

In one embodiment, the method further comprises receiving the pluralityof synchronization signal blocks by using a plurality of receive beamsand determining the matching receive beam of the terminal device basedon reception quality.

In one embodiment, the wireless communication system has beam symmetry,the method further comprising transmitting to the base station the RApreamble by using the transmit beam at the terminal device sidecorresponding to the matching receive beam of the terminal device.

In one embodiment, the method further comprises, in a case where a RAresponse by the base station is not received within a predetermined timeperiod after transmitting the RA preamble, retransmitting the RApreamble by using a transmit beam around the transmit beam at theterminal device side.

For example, according to still another aspect of the presentdisclosure, an electronic device for a base station side in a wirelesscommunication system comprises a processing circuitry configured to:transmit, by using different transmit beams at the base station side, aplurality of synchronization signal blocks including, respectively, aPSS, a SSS and a PBCH, to a terminal device in the wirelesscommunication system for downlink synchronization, wherein eachsynchronization signal block can indicate information of a transmit beamused to transmit the synchronization signal block by the base station;receive a RA preamble from the terminal device to assist a RA process ofthe terminal device, wherein the RA preamble can indicate information ofthe transmit beam for the synchronization signal block that matches withthe terminal device; determine, according to the RA preamble, a transmitbeam at the base station side suitable for downlink transmission to theterminal device for beam management.

In one embodiment, the synchronization signal block indicates, by areference signal sequence per se in the synchronization signal block,information of the transmit beam used to transmit the synchronizationsignal block by the base station, and the processing circuitry isfurther configured to place different reference signal sequences in theplurality of synchronization signal blocks to indicate information ofdifferent transmit beams.

In one embodiment, the synchronization signal block further comprisesadditional information bits by which to indicate information of thetransmit beam used to transmit the synchronization signal block by thebase station, and the processing circuitry is further configured toplace different additional information bits in the plurality ofsynchronization signal blocks to indicate information of differenttransmit beams.

In one embodiment, the preamble sequence of the RA preamble indicatesinformation of the transmit beam for the synchronization signal blockthat matches with the terminal device.

In one embodiment, a plurality of preamble sequences are used toindicate information of the transmit beam for a same synchronizationsignal block, and the base station transmits a signaling to the terminaldevice for indicating correspondence between a plurality of preamblesequences and the transmit beam for the synchronization signal block.

In one embodiment, the processing circuitry is further configured totransmit, to the terminal device, a radio resource control signalingincluding RA configuration information, and the RA configurationinformation comprises correspondence between beams at the base stationside and a plurality of RA occasions, so that the terminal deviceselects, according to the RA configuration information, a specific RAoccasion to transmit a RA preamble, to indicate information of thetransmit beam for the matching synchronization signal block.

In one embodiment, the processing circuitry is further configured totransmit a CSI-RS beam in a transmit beam direction corresponding to thematching synchronization signal block, and to receive, from the terminaldevice, feedback of the information of the CSI-RS beam that matches withthe terminal device.

In one embodiment, the wireless communication system is a 5G NR system,the base station is a gNB, and the base station further includes aplurality of antennas for transmitting signals by beamforming.

For example, according to still another aspect of the presentdisclosure, a method for a base station side in a wireless communicationsystem comprises: transmitting, by using different transmit beams at thebase station side, a plurality of Synchronization Signal blocksincluding, respectively, a PSS, a SSS and a PBCH, to a terminal devicein the wireless communication system for downlink synchronization,wherein each synchronization signal block can indicate information ofthe transmit beam used to transmit the synchronization signal block bythe base station; receiving a RA preamble from the terminal device toassist a RA process of the terminal device, wherein the RA preamble canindicate information of the transmit beam for the synchronization signalblock that matches with the terminal device; and determining, accordingto the RA preamble, a transmit beam at the base station side suitablefor downlink transmission to the terminal device for beam management.

In one embodiment, the synchronization signal block indicates, by areference signal sequence per se in the synchronization signal block,information of the transmit beam used to transmit the synchronizationsignal block by the base station, and the method further comprisingplacing different reference signal sequences in the plurality ofsynchronization signal blocks to indicate information of differenttransmit beams.

In one embodiment, the synchronization signal block further comprisesadditional information bits by which to indicate information of thetransmit beam used to transmit the synchronization signal block by thebase station, and the method further comprising placing differentadditional information bits in the plurality of synchronization signalblocks to indicate information of different transmit beams.

In one embodiment, the preamble sequence of the RA preamble indicatesinformation of the transmit beam for the synchronization signal blockthat matches with the terminal device.

In one embodiment, a plurality of preamble sequences are used toindicate information of the transmit beam for a same synchronizationsignal block, and the method further comprising transmitting a signalingto the terminal device for indicating correspondence between a pluralityof preamble sequences and the transmit beam for the synchronizationsignal block.

In one embodiment, the method further comprises transmitting, to theterminal device, a radio resource control signaling including RAconfiguration information, and the RA configuration informationcomprises correspondence between beams at the base station side and aplurality of RA occasions, so that the terminal device selects,according to the RA configuration information, a specific RA occasion totransmit a RA preamble to indicate information of the transmit beam forthe matching synchronization signal block.

In one embodiment, the method further comprises transmitting a CSI-RSbeam in a transmit beam direction corresponding to the matchingsynchronization signal block, and receiving, from the terminal device,feedback of the information of the CSI-RS beam that matches with theterminal device.

It should be understood that the machine-executable instructions in thestorage medium and the program product according to the embodimentsherein can also be configured to perform the methods corresponding tothe apparatus embodiment described above, and thus the content notdescribed in detail herein can be referred to the description in theprevious corresponding positions, thus the description thereof will notbe repeated herein.

Accordingly, a storage medium for carrying the above-described programproduct including machine executable instructions is also included inthe disclosure of the present invention. The storage medium includes,but is not limited to, a floppy disk, an optical disk, a magneto-opticaldisk, a memory card, a memory stick, and the like.

In addition, it should also be noted that the above series of processesand devices can also be implemented by software and/or firmware. In thecase of being implemented by software and/or firmware, a programconstituting the software is installed from a storage medium or anetwork to a computer having a dedicated hardware structure, such as thegeneral-purpose personal computer 1300 shown in FIG. 24 , which, when isinstalled with various programs, can execute various functions and soon. FIG. 24 is a block diagram showing an example structure of apersonal computer which can be employed as an information processingdevice in the embodiment herein. In one example, the personal computercan correspond to the above-described exemplary terminal device inaccordance with the present disclosure.

In FIG. 24 , a central processing unit (CPU) 1301 executes variousprocesses in accordance with a program stored in a read-only memory(ROM) 1302 or a program loaded from a storage 1308 to a random accessmemory (RAM) 1303. In the RAM 1303, data required when the CPU 1301executes various processes and the like is also stored as needed.

The CPU 1301, the ROM 1302, and the RAM 1303 are connected to each othervia a bus 1304. Input/output interface 1305 is also connected to bus1304.

The following components are connected to the input/output interface1305: an input unit 1306 including a keyboard, a mouse, etc.; an outputunit 1307 including a display such as a cathode ray tube (CRT), a liquidcrystal display (LCD), etc., and a speaker, etc.; the storage 1308including a hard disk etc.; and a communication unit 1309 including anetwork interface card such as a LAN card, a modem, etc. Thecommunication unit 1309 performs communication processing via a networksuch as the Internet.

A driver 1310 is also connected to the input/output interface 1305 asneeded. A removable medium 1311 such as a magnetic disk, an opticaldisk, a magneto-optical disk, a semiconductor memory or the like ismounted on the drive 1310 as needed, so that a computer program readtherefrom is installed into the storage 1308 as needed.

In the case where the above-described series of processing isimplemented by software, a program constituting the software isinstalled from a network such as the Internet or a storage medium suchas the removable medium 1311.

It will be understood by those skilled in the art that such a storagemedium is not limited to the removable medium 1311 shown in FIG. 24 inwhich a program is stored and distributed separately from the device toprovide a program to the user. Examples of the removable medium 1311include a magnetic disk (including a floppy disk (registeredtrademark)), an optical disk (including a compact disk read only memory(CD-ROM) and a digital versatile disk (DVD)), a magneto-optical disk(including a mini disk (MD) (registered trademark)) and a semiconductormemory. Alternatively, the storage medium may be a ROM 1302, a hard diskincluded in the storage section 1308, or the like, in which programs arestored, and distributed to users together with the device containingthem.

The technology of the present disclosure can be applied to variousproducts. For example, the base stations mentioned in this disclosurecan be implemented as any type of evolved Node B (eNB), such as a macroeNB and a small eNB. The small eNB can be an eNB covering a cell smallerthan the macro cell, such as a pico eNB, a micro eNB, and a home (femto)eNB. Alternatively, the base station can be implemented as any othertype of base station, such as a NodeB and a Base Transceiver Station(BTS). The base station can include: a body (also referred to as a basestation device) configured to control radio communication; and one ormore remote radio heads (RRHs) disposed at a different location from thebody. In addition, various types of terminals which will be describedbelow can each operate as a base station by performing base stationfunctions temporarily or semi-persistently.

For example, the terminal device mentioned in the present disclosure,also referred to as a user device in some examples, can be implementedas a mobile terminal (such as a smartphone, a tablet personal computer(PC), a notebook PC, a portable game terminal, a portable/dongle typemobile router and digital camera) or in-vehicle terminal (such as carnavigation device). The user device may also be implemented as aterminal that performs machine-to-machine (M2M) communication (alsoreferred to as a machine type communication (MTC) terminal). Further,the user device may be a radio communication module (such as anintegrated circuit module including a single wafer) installed on each ofthe above terminals.

Use cases according to the present disclosure will be described belowwith reference to FIGS. 25 to 28 .

[Use Cases for Base Stations]

It should be understood that the term base station in this disclosurehas the full breadth of its ordinary meaning, and includes at least aradio communication station used as portion of a wireless communicationsystem or radio system to facilitate communication. Examples of the basestation can be, for example but not limited to, the following: the basestation can be either or both of a base transceiver station (BTS) and abase station controller (BSC) in the GSM system, and can be either orboth of a radio network controller (RNC) or Node B in the WCDMA system,can be eNB in the LTE and LTE-Advanced system, or can be correspondingnetwork nodes in future communication systems (e.g., the gNB that canappear in the 5G communication systems, eLTE eNB, etc.). Some of thefunctions in the base station of the present disclosure can also beimplemented as an entity having a control function for communication inthe scenario of a D2D, M2M, and V2V communication, or as an entity thatplays a spectrum coordination role in the scenario of a cognitive radiocommunication.

First Use Case

FIG. 25 is a block diagram illustrating a first example of a schematicconfiguration of a gNB to which the technology of the present disclosurecan be applied. The gNB 1400 includes a plurality of antennas 1410 and abase station device 1420. The base station device 1420 and each antenna1410 may be connected to each other via an RF cable. In oneimplementation, the gNB 1400 (or base station device 1420) herein maycorrespond to the electronic devices 300A, 1300A, and/or 1500B describedabove.

Each of the antennas 1410 includes a single or multiple antenna elements(such as multiple antenna elements included in a Multiple Input andMultiple Output (MIMO) antenna), and is used for the base station device1420 to transmit and receive radio signals. As shown in FIG. 25 , thegNB 1400 may include multiple antennas 1410. For example, multipleantennas 1410 may be compatible with multiple frequency bands used bythe gNB 1400.

The base station device 1420 includes a controller 1421, a memory 1422,a network interface 1423, and a radio communication interface 1425.

The controller 1421 may be, for example, a CPU or a DSP, and operatesvarious functions of higher layers of the base station device 1420. Forexample, controller 1421 generates data packets from data in signalsprocessed by the radio communication interface 1425, and transfers thegenerated packets via network interface 1423. The controller 1421 canbundle data from multiple base band processors to generate the bundledpackets, and transfer the generated bundled packets. The controller 1421may have logic functions of performing control such as radio resourcecontrol, radio bearer control, mobility management, admission control,and scheduling. This control may be performed in corporation with a gNBor a core network node in the vicinity. The memory 1422 includes RAM andROM, and stores a program that is executed by the controller 1421 andvarious types of control data such as a terminal list, transmissionpower data, and scheduling data.

The network interface 1423 is a communication interface for connectingthe base station device 1420 to the core network 1424. Controller 1421may communicate with a core network node or another gNB via the networkinterface 1423. In this case, the gNB 1400 and the core network node orother gNBs may be connected to each other through a logical interfacesuch as an S1 interface and an X2 interface. The network interface 1423may also be a wired communication interface or a radio communicationinterface for radio backhaul lines. If the network interface 1423 is aradio communication interface, the network interface 1423 may use ahigher frequency band for radio communication than a frequency band usedby the radio communication interface 1425.

The radio communication interface 1425 supports any cellularcommunication schemes, such as Long Term Evolution (LTE) andLTE-Advanced, and provides radio connection to a terminal positioned ina cell of the gNB 1400 via the antenna 1410. Radio communicationinterface 1425 may typically include, for example, a baseband (BB)processor 1426 and a RF circuit 1427. The BB processor 1426 may perform,for example, encoding/decoding, modulation/demodulation, andmultiplexing/demultiplexing, and performs various types of signalprocessing of layers such as L1, Medium Access Control (MAC), Radio LinkControl (RLC), and Packet Data Convergence Protocol (PDCP). Instead ofcontroller 1421, the BB processor 1426 may have a part or all of theabove-described logic functions. The BB processor 1426 may be a memorythat stores a communication control program, or a module that includes aprocessor configured to execute the program and a related circuit.Updating the program may allow the functions of the BB processor 1426 tobe changed. The module may be a card or a blade that is inserted into aslot of the base station device 1420. Alternatively, the module may alsobe a chip that is mounted on the card or the blade. Meanwhile, the RFcircuit 1427 may include, for example, a mixer, a filter, and anamplifier, and transmits and receives radio signals via the antenna1410. Although FIG. 25 illustrates an example in which one RF circuit1427 is connected to one antenna 1410, the present disclosure is notlimited to thereto; rather, one RF circuit 1427 may connect to aplurality of antennas 1410 at the same time.

As illustrated in FIG. 25 , the radio communication interface 1425 mayinclude the multiple BB processors 1426. For example, the multiple BBprocessors 1426 may be compatible with multiple frequency bands used bygNB 1400. As illustrated in FIG. 25 , the radio communication interface1425 may include the multiple RF circuits 1427. For example, themultiple RF circuits 1427 may be compatible with multiple antennaelements. Although FIG. 25 illustrates the example in which the radiocommunication interface 1425 includes the multiple BB processors 1426and the multiple RF circuits 1427, the radio communication interface1425 may also include a single BB processor 1426 or a single RF circuit1427.

Second Use Case

FIG. 26 is a block diagram illustrating a second example of a schematicconfiguration of a gNB to which the technology of the present disclosuremay be applied. The gNB 1530 includes a plurality of antennas 1540, abase station device 1550, and an RRH 1560. The RRH 1560 and each antenna1540 may be connected to each other via an RF cable. The base stationdevice 1550 and the RRH 1560 may be connected to each other via a highspeed line such as a fiber optic cable. In one implementation, the gNB1530 (or base station device 1550) herein may correspond to theelectronic devices 300A, 1300A, and/or 1500B described above.

Each of the antennas 1540 includes a single or multiple antenna elementssuch as multiple antenna elements included in a MIMO antenna and is usedfor the RRH 1560 to transmit and receive radio signals. The gNB 1530 mayinclude multiple antennas 1540, as illustrated in FIG. 26 . For example,multiple antennas 1540 may be compatible with multiple frequency bandsused by the gNB 1530.

The base station device 1550 includes a controller 1551, a memory 1552,a network interface 1553, a radio communication interface 1555, and aconnection interface 1557. The controller 1551, the memory 1552, and thenetwork interface 1553 are the same as the controller 1421, the memory1422, and the network interface 1423 described with reference to FIG. 25.

The radio communication interface 1555 supports any cellularcommunication scheme (such as LTE and LTE-Advanced) and provides radiocommunication to terminals positioned in a sector corresponding to theRRH 1560 via the RRH 1560 and the antenna 1540. The radio communicationinterface 1555 may typically include, for example, a BB processor 1556.The BB processor 1556 is the same as the BB processor 1426 describedwith reference to FIG. 25 , except that the BB processor 1556 isconnected to the RF circuit 1564 of the RRH 1560 via the connectioninterface 1557. The radio communication interface 1555 may include themultiple BB processors 1556, as illustrated in FIG. 26 . For example,the multiple BB processors 1556 may be compatible with multiplefrequency bands used by the gNB 1530. Although FIG. 26 illustrates theexample in which the radio communication interface 1555 includesmultiple BB processors 1556, the radio communication interface 1555 mayalso include a single BB processor 1556.

The connection interface 1557 is an interface for connecting the basestation device 1550 (radio communication interface 1555) to the RRH1560. The connection interface 1557 may also be a communication modulefor communication in the above-described high speed line that connectsthe base station device 1550 (radio communication interface 1555) to theRRH 1560.

The RRH 1560 includes a connection interface 1561 and a radiocommunication interface 1563.

The connection interface 1561 is an interface for connecting the RRH1560 (radio communication interface 1563) to the base station device1550. The connection interface 1561 may also be a communication modulefor communication in the above-described high speed line.

The radio communication interface 1563 transmits and receives radiosignals via the antenna 1540. Radio communication interface 1563 maytypically include, for example, the RF circuitry 1564. The RF circuit1564 may include, for example, a mixer, a filter, and an amplifier, andtransmits and receives radio signals via the antenna 1540. Although FIG.26 illustrates the example in which one RF circuit 1564 is connected toone antenna 1540, the present disclosure is not limited to thereto;rather, one RF circuit 1564 may connect to a plurality of antennas 1540at the same time.

The radio communication interface 1563 may include multiple RF circuits1564, as illustrated in FIG. 26 . For example, multiple RF circuits 1564may support multiple antenna elements. Although FIG. 26 illustrates theexample in which the radio communication interface 1563 includes themultiple RF circuits 1564, the radio communication interface 1563 mayalso include a single RF circuit 1564.

[Use Cases Related to User Devices]

First Use Case

FIG. 27 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 1600 to which the technology of thepresent disclosure may be applied. The smartphone 1600 includes aprocessor 1601, a memory 1602, a storage 1603, an external connectioninterface 1604, an camera 1606, a sensor 1607, a microphone 1608, aninput device 1609, a display device 1610, a speaker 1611, a radiocommunication interface 1612, one or more antenna switch 1615, one ormore antennas 1616, a bus 1617, a battery 1618, and an auxiliarycontroller 1619. In one implementation, smartphone 1600 (or processor1601) herein may correspond to terminal device 300B and/or 1500Adescribed above.

The processor 1601 may be, for example, a CPU or a system on chip (SoC),and controls functions of an application layer and the other layers ofthe smartphone 1600. The memory 1602 includes RAM and ROM, and stores aprogram that is executed by the processor 1601, and data. The storage1603 may include a storage medium such as a semiconductor memory and ahard disk. The external connection interface 1604 is an interface forconnecting an external device such as a memory card and a universalserial bus (USB) device to the smartphone 1600.

The camera 1606 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. Sensor 1607 may include a group of sensorssuch as a measurement sensor, a gyro sensor, a geomagnetic sensor, andan acceleration sensor. The microphone 1608 converts the sounds that areinput to the smartphone 1600 to audio signals. The input device 1609includes, for example, a touch sensor configured to detect touch on ascreen of the display device 1610, a keypad, a keyboard, a button, or aswitch, and receives an operation or an information input from a user.The display device 1610 includes a screen such as a liquid crystaldisplay (LCD) and an organic light emitting diode (OLED) display, anddisplays an output image of the smartphone 1600. The speaker 1611converts audio signals that are output from the smartphone 1600 tosounds.

The radio communication interface 1612 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and performs radiocommunication. The radio communication interface 1612 may typicallyinclude, for example, a BB processor 1613 and an RF circuitry 1614. TheBB processor 1613 may perform, for example, encoding/decoding,modulation/demodulation, and multiplexing/demultiplexing, and performsvarious types of signal processing for radio communication. Meanwhile,the RF circuit 1614 may include, for example, a mixer, a filter, and anamplifier, and transmits and receives radio signals via the antenna1616. The radio communication interface 1612 may be a one chip modulethat integrates the BB processor 1613 and the RF circuit 1614 thereon.The radio communication interface 1612 may include multiple BBprocessors 1613 and multiple RF circuits 1614, as illustrated in FIG. 27. Although FIG. 27 illustrates the example in which the radiocommunication interface 1612 includes multiple BB processors 1613 andmultiple RF circuits 1614, the radio communication interface 1612 mayalso include a single BB processor 1613 or a single RF circuit 1614.

Furthermore, in addition to a cellular communication scheme, the radiocommunication interface 1612 may support additional type of radiocommunication schemes, such as short-range wireless communicationschemes, a near field communication schemes, and a wireless local areanetwork (LAN) scheme. In this case, the radio communication interface1612 may include the BB processor 1613 and the RF circuitry 1614 foreach radio communication scheme.

Each of the antenna switches 1615 switches connection destinations ofthe antenna 1616 among multiple circuits (such as circuits for differentradio communication schemes) included in the radio communicationinterface 1612.

Each of the antennas 1616 includes a single or multiple antenna elements(such as multiple antenna elements included in a MIMO antenna) and isused for the radio communication interface 1612 to transmit and receiveradio signals. The smartphone 1600 may include multiple antennas 1616,as illustrated in FIG. 27 . Although FIG. 27 illustrates the example inwhich the smartphone 1600 includes multiple antennas 1616, thesmartphone 1600 may also include a single antenna 1616.

Furthermore, the smartphone 1600 may include the antenna 1616 for eachradio communication scheme. In this case, the antenna switch 1615 may beomitted from the configuration of the smartphone 1600.

The bus 1617 connects the processor 1601, the memory 1602, the storage1603, the external connection interface 1604, the camera 1606, thesensor 1607, the microphone 1608, the input device 1609, the displaydevice 1610, the speaker 1611, the radio communication interface 1612,and the auxiliary control 1619 to each other. The battery 1618 suppliespower to blocks of the smartphone 1600 illustrated in FIG. 27 via feederlines, which are partially shown as a dashed line in the figure. Theauxiliary controller 1619 operates a minimum necessary function of thesmartphone 1600, for example, in a sleep mode.

Second Use Case

FIG. 28 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 1720 to which the technology ofthe present disclosure may be applied. The car navigation device 1720includes a processor 1721, a memory 1722, a global positioning system(GPS) module 1724, a sensor 1725, a data interface 1726, a contentplayer 1727, a storage medium interface 1728, an input device 1729, adisplay device 1730, a speaker 1731, and a radio communication interface1733, one or more antenna switches 1736, one or more antennas 1737, anda battery 1738. In one implementation, car navigation device 1720 (orprocessor 1721) herein may correspond to terminal device 300B and/or1500A described above.

The processor 1721 may be, for example, a CPU or a SoC, and controls anavigation function and other functions of the car navigation device1720. The memory 1722 includes RAM and ROM, and stores a program that isexecuted by the processor 1721, and data.

The GPS module 1724 uses GPS signals received from a GPS satellite tomeasure a position, such as latitude, longitude, and altitude, of thecar navigation device 1720. Sensor 1725 may include a group of sensorssuch as a gyro sensor, a geomagnetic sensor, and an air pressure sensor.The data interface 1726 is connected to, for example, an in-vehiclenetwork 1741 via a terminal not shown, and acquires data generated bythe vehicle, such as vehicle speed data.

The content player 1727 reproduces content stored in a storage medium(such as a CD and a DVD) that is inserted into the storage mediuminterface 1728. The input device 1729 includes, for example, a touchsensor configured to detect touch on a screen of the display device1730, a button, or a switch, and receives an operation or an informationinput from a user. The display device 1730 includes a screen such as anLCD or an OLED display, and displays an image of the navigation functionor content that is reproduced. The speaker 1731 outputs sounds of thenavigation function or the content that is reproduced.

The radio communication interface 1733 supports any cellularcommunication scheme, such as LTE and LTE-Advanced, and performs radiocommunication. The radio communication interface 1733 may typicallyinclude, for example, a BB processor 1734 and an RF circuit 1735. The BBprocessor 1734 may perform, for example, encoding/decoding,modulation/demodulation, and multiplexing/demultiplexing, and performsvarious types of signal processing for radio communication. Meanwhile,the RF circuit 1735 may include, for example, a mixer, a filter, and anamplifier, and transmits and receives radio signals via the antenna1737. The radio communication interface 1733 may also be a one chipmodule which integrates the BB processor 1734 and the RF circuit 1735thereon. The radio communication interface 1733 may include multiple BBprocessors 1734 and multiple RF circuits 1735, as illustrated in FIG. 28. Although FIG. 28 illustrates the example in which the radiocommunication interface 1733 includes multiple BB processors 1734 andmultiple RF circuits 1735, the radio communication interface 1733 mayalso include a single BB processor 1734 or a single RF circuit 1735.

Furthermore, in addition to a cellular communication scheme, the radiocommunication interface 1733 may support another type of radiocommunication scheme such as a short-range wireless communicationscheme, a near-field communication scheme, and a wireless LAN scheme. Inthis case, the radio communication interface 1733 may include the BBprocessor 1734 and the RF circuit 1735 for each radio communicationscheme.

Each of the antenna switches 1736 switches the connection destination ofthe antenna 1737 among multiple circuits (such as circuits for differentradio communication schemes) included in the radio communicationinterface 1733.

Each of the antennas 1737 includes a single or multiple antennaelements, such as multiple antenna elements included in a MIMO antenna,and is used for the radio communication interface 1733 to transmit andreceive radio signals. The car navigation device 1720 may includemultiple antennas 1737, as illustrated in FIG. 28 . Although FIG. 28illustrates the example in which the car navigation device 1720 includesmultiple antennas 1737, the car navigation device 1720 may also includea single antenna 1737.

Furthermore, the car navigation device 1720 may include the antenna 1737for each radio communication scheme. In this case, the antenna switch1736 may be omitted from the configuration of the car navigation device1720.

The battery 1738 supplies power to blocks of the car navigation device1720 illustrated in FIG. 28 via feeder lines that are partially shown asdashed lines in the figure. Battery 1738 accumulates power supplied fromthe vehicle.

The technology of the present disclosure may also be realized as anin-vehicle system (or vehicle) 1740 including one or more blocks of thecar navigation device 1720, the in-vehicle network 1741, and the vehiclemodule 1742. The vehicle module 1742 generates vehicle data such asvehicle speed, engine speed, and faults information, and outputs thegenerated data to the in-vehicle network 1741.

Although the illustrative embodiments herein have been described withreference to the accompanying drawings, the present disclosure iscertainly not limited to the above examples. Those skilled in the artcan achieve various adaptions and modifications within the scope of theappended claims, and it will be appreciated that these adaptions andmodifications certainly fall into the scope of the technology of thepresent disclosure.

For example, in the above embodiments, the multiple functions includedin one module can be implemented by separate means. Alternatively, inthe above embodiments, the multiple functions included in multiplemodules can be implemented by separate means, respectively. Inadditions, one of the above functions can be implemented by multipleunits. Needless to say, such configurations are included in the scope ofthe technology of the present disclosure.

In this specification, the steps described in the flowcharts include notonly the processes performed sequentially in chronological order, butalso the processes performed in parallel or separately but notnecessarily performed in chronological order. Furthermore, even in thesteps performed in chronological order, needless to say, the order canbe changed appropriately.

Although the present disclosure and its advantages have been describedin detail, it will be appreciated that various changes, replacements andtransformations can be made without departing from the spirit and scopeof the present disclosure as defined by the appended claims. Inaddition, the terms “include”, “comprise” or any other variants of theembodiments herein are intended to be non-exclusive inclusion, such thatthe process, method, article or device including a series of elementsincludes not only these elements, but also those that are not listedspecifically, or those that are inherent to the process, method, articleor device. In case of further limitations, the element defined by thesentence “include one” does not exclude the presence of additional sameelements in the process, method, article or device including thiselement.

What is claimed is:
 1. An electronic device for a terminal device sidein a wireless communication system, comprising a processing circuitryconfigured to: receive, from a Base Station (BS) in the wirelesscommunication system, a plurality of Synchronization Signal (SS) blocksincluding, respectively, a primary SS (PSS), a secondary SS (SSS), and aPBCH for downlink synchronization, wherein the plurality of SS blocksare transmitted by different transmit (TX) beams at the BS side, andeach SS block indicates information of a TX beam used to transmit the SSblock by the BS; determine a SS block that matches with the terminaldevice based on the SS block in which signal reception quality satisfiesa predetermined condition; and transmit a random access preamble to theBS to perform a random access process, wherein the random accesspreamble indicates the information of the TX beam used to transmit thematching SS block by the BS; wherein the processing circuitry isconfigured to: obtain services of the BS and another base station thatdoes not perform beamforming transceiving by way of dual connectivity,and obtain information of the random access preamble indicating the TXbeam used to transmit the matching SS block by the BS, from the anotherbase station.
 2. The electronic device of claim 1, wherein theprocessing circuitry is further configured to obtain, from the anotherbase station, information about correspondence between each of receive,RX, beams at the BS side and time domain resources to be used fortransmitting random access preambles and determine the random accesspreamble indicating the TX beam used to transmit the matching SS block.3. The electronic device of claim 1, wherein a plurality of preamblesequences of the random access preamble are divided into multiplegroups, all of the preamble sequences in each of the multiple groups areused to indicate information of the TX beam for a same SS block.
 4. Theelectronic device of claim 3, wherein transmissions using all of thepreamble sequences in said each of the multiple groups are multiplexedby time.
 5. The electronic device of claim 1, wherein the SS blockindicates, by a reference signal sequence per se in the SS block,information of the TX beam used to transmit the SS block by the BS, orwherein the SS block further comprises additional information bits bywhich to indicate information of the TX beam used to transmit the SSblock by the BS.
 6. The electronic device of claim 1, wherein theprocessing circuitry is further configured to: receive, from the BS, aradio resource control signaling including random access configurationinformation, wherein the random access configuration informationcomprises correspondence between beams at the BS side and a plurality ofrandom access occasions; and select a specific random access occasion totransmit a random access preamble according to the random accessconfiguration information, to indicate information of the TX beam usedto transmit the matching SS block by the BS.
 7. The electronic device ofclaim 1, wherein the processing circuitry is further configured toreceive a CSI-RS beam transmitted by the BS in a TX beam directioncorresponding to the matching SS block, and feedback information of theCSI-RS beam matching with the terminal device to the BS.
 8. Anelectronic device for a Base Station (BS) side in a wirelesscommunication system, comprising a processing circuitry configured to:transmit, by using different transmit (TX) beams at the BS side, aplurality of synchronization signal (SS) blocks including, respectively,a primary SS (PSS), a secondary SS (SSS), and a PBCH to a terminaldevice in the wireless communication system for downlinksynchronization, wherein each SS block indicates information of a TXbeam used to transmit the SS block by the BS; receive a random accesspreamble from the terminal device, wherein the random access preambleindicates information of the TX beam for the SS block that matches withthe terminal device; and determine, according to the random accesspreamble, a TX beam at the BS side suitable for downlink transmission tothe terminal device; wherein the processing circuitry is configured to:provide information of the random access preamble indicating the TX beamused to transmit the matching SS block, to another base station thatserves the terminal device together with the BS by way of dualconnectivity and does not perform beamforming transceiving; wherein theinformation of the random access preamble is sent to the terminal deviceby the another base station.
 9. The electronic device of claim 8,wherein a plurality of preamble sequences of the random access preambleare divided into multiple groups, all of the preamble sequences in eachof the multiple groups are used to indicate information of the TX beamfor a same SS block.
 10. The electronic device of claim 9, whereintransmissions using all of the preamble sequences in said each of themultiple groups are multiplexed by time.
 11. The electronic device ofclaim 8, wherein the SS block indicates, by a reference signal sequenceper se in the SS block, information of the TX beam used to transmit theSS block by the BS, or wherein the SS block further comprises additionalinformation bits by which to indicate information of the TX beam used totransmit the SS block by the BS.
 12. The electronic device of claim 8,wherein the processing circuitry is further configured to transmit, tothe terminal device, a radio resource control signaling including randomaccess configuration information, and the random access configurationinformation comprises correspondence between beams at the BS side and aplurality of random access occasions, so that the terminal deviceselects, according to the random access configuration information, aspecific random access occasion to transmit a random access preamble toindicate information of the TX beam for the matching SS block.
 13. Theelectronic device of claim 8, wherein the processing circuitry isfurther configured to transmit a CSI-RS beam in a TX beam directioncorresponding to the matching SS block, and to receive, from theterminal device, feedback of information of the CSI-RS beam that matcheswith the terminal device.
 14. The electronic device of claim 8, whereinthe terminal device is further configured to obtain, from the anotherbase station, information about correspondence between each of receive,RX, beams at the BS side and time domain resources to be used fortransmitting random access preambles and determine the random accesspreamble indicating the TX beam used to transmit the matching SS block.15. A method performed by a Base Station (BS) comprising: transmitting,by using different transmit (TX) beams at the BS side, a plurality ofsynchronization signal (SS) blocks including, respectively, a primary SS(PSS), a secondary SS (SSS), and a PBCH to a terminal device in thewireless communication system for downlink synchronization, wherein eachSS block indicates information of a TX beam used to transmit the SSblock by the BS; receiving a random access preamble from the terminaldevice, wherein the random access preamble indicates information of theTX beam for the SS block that matches with the terminal device; anddetermining, according to the random access preamble, a TX beam at theBS side suitable for downlink transmission to the terminal device; andproviding information of the random access preamble indicating the TXbeam used to transmit the matching SS block, to another base stationthat serves the terminal device together with the BS by way of dualconnectivity and does not perform beamforming transceiving; wherein theinformation of the random access preamble is sent to the terminal deviceby the another base station.
 16. The method of claim 15, wherein aplurality of preamble sequences of the random access preamble aredivided into multiple groups, all of the preamble sequences in each ofthe multiple groups are used to indicate information of the TX beam fora same SS block.
 17. The method of claim 16, wherein transmissions usingall of the preamble sequences in said each of the multiple groups aremultiplexed by time.
 18. The method of claim 15, wherein the SS blockindicates, by a reference signal sequence per se in the SS block,information of the TX beam used to transmit the SS block by the BS, orwherein the SS block further comprises additional information bits bywhich to indicate information of the TX beam used to transmit the SSblock by the BS.
 19. The method of claim 15, further comprising:transmitting, to the terminal device, a radio resource control signalingincluding random access configuration information; wherein the randomaccess configuration information comprises correspondence between beamsat the BS side and a plurality of random access occasions, so that theterminal device selects, according to the random access configurationinformation, a specific random access occasion to transmit a randomaccess preamble to indicate information of the TX beam for the matchingSS block.
 20. The method of claim 15, further comprising: transmitting aCSI-RS beam in a TX beam direction corresponding to the matching SSblock, and to receive, from the terminal device, feedback of informationof the CSI-RS beam that matches with the terminal device.